1. Product profile
1.1 General description
N-channel symmetrical silicon junction field-effect transistors in a SOT23 package.
1.2 Features and benefits
 Low leakage level (typ. 500 fA)
 High gain
 Low cut-off voltage (max. 2.2 V for BF545A).
1.3 Applications
 Impedance converters in e.g. electret microphones and infra-red detectors
 VHF amplifiers in oscillators and mixers.
1.4 Quick reference data
BF545A; BF545B; BF545C
N-channel silicon junction field-effect transistors
Rev. 4 — 15 September 2011 Product data sheet
SOT23
CAUTION
This device is sensitive to ElectroStatic Discharge (ESD). Therefore care should be taken
during transport and handling.
Table 1. Quick reference data
Symbol Parameter Conditions Min Typ Max Unit
VDS drain-source voltage - - 30 V
VGSoff gate-source cut-off
voltage
ID = 1 A; VDS = 15 V 0.4 - 7.8 V
IDSS drain current VGS = 0 V; VDS = 15 V
BF545A 2 - 6.5 mA
BF545B 6 - 15 mA
BF545C 12 - 25 mA
Ptot total power dissipation Tamb  25 C - - 250 mW
yfs forward transfer
admittance
VGS = 0 V; VDS = 15 V 3 - 6.5 mS
BF545A_BF545B_BF545C All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 4 — 15 September 2011 2 of 16
NXP Semiconductors BF545A; BF545B; BF545C
N-channel silicon junction field-effect transistors)
2. Pinning information
3. Ordering information
4. Marking
[1] * = p: made in Hong Kong.
* = t: made in Malaysia.
* = W: made in China.
Table 2. Pinning
Pin Description Simplified outline Symbol
1 source (s)
2 drain (d)
3 gate (g)
1 2
3
sym054
d
sg
Table 3. Ordering information
Type number Package
Name Description Version
BF545A - plastic surface mounted package; 3 leads SOT23
BF545B
BF545C
Table 4. Marking
Type number Marking code[1]
BF545A 20*
BF545B 21*
BF545C 22*
BF545A_BF545B_BF545C All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 4 — 15 September 2011 3 of 16
NXP Semiconductors BF545A; BF545B; BF545C
N-channel silicon junction field-effect transistors)
5. Limiting values
[1] Device mounted on an FR4 printed-circuit board, maximum lead length 4 mm; mounting pad for the drain
lead 10 mm2.
6. Thermal characteristics
[1] Device mounted on an FR4 printed-circuit board, maximum lead length 4 mm; mounting pad for the drain
lead 10 mm2.
Table 5. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol Parameter Conditions Min Max Unit
VDS drain-source voltage (DC) - 30 V
VGSO gate-source voltage open drain - 30 V
VGDO gate-drain voltage (DC) open source - 30 V
IG forward gate current (DC) - 10 mA
Ptot total power dissipation Tamb  25 C [1] - 250 mW
Tstg storage temperature 65 +150 C
Tj junction temperature - 150 C
Fig 1. Power derating curve.
Tamb (°C)
0 20015050 100
mbb688
200
100
300
400
Ptot
(mW)
0
Table 6. Thermal characteristics
Symbol Parameter Conditions Typ Unit
Rth(j-a) thermal resistance from junction to
ambient
[1] 500 K/W
BF545A_BF545B_BF545C All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 4 — 15 September 2011 4 of 16
NXP Semiconductors BF545A; BF545B; BF545C
N-channel silicon junction field-effect transistors)
7. Static characteristics
Table 7. Static characteristics
Tj = 25 C unless otherwise specified.
Symbol Parameter Conditions Min Typ Max Unit
V(BR)GSS gate-source breakdown voltage IG = 1 A; VDS = 0 V 30 - - V
VGSoff gate-source cut-off voltage ID = 200 A; VDS = 15 V
BF545A 0.4 - 2.2 V
BF545B 1.6 - 3.8 V
BF545C 3.2 - 7.8 V
ID = 1 A; VDS = 15 V 0.4 - 7.5 V
IDSS drain current VGS = 0 V; VDS = 15 V
BF545A 2 - 6.5 mA
BF545B 6 - 15 mA
BF545C 12 - 25 mA
IGSS gate-source leakage current VGS = 20 V; VDS = 0 V - 0.5 1000 pA
VGS = 20 V; VDS = 0 V;
Tj = 125 C
- - 100 nA
yfs forward transfer admittance VGS = 0 V; VDS = 15 V 3 - 6.5 mS
yos common source output
admittance
VGS = 0 V; VDS = 15 V - 40 - S
BF545A_BF545B_BF545C All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 4 — 15 September 2011 5 of 16
NXP Semiconductors BF545A; BF545B; BF545C
N-channel silicon junction field-effect transistors)
8. Dynamic characteristics
Table 8. Dynamic characteristics
Tamb = 25 C unless otherwise specified.
Symbol Parameter Conditions Min Typ Max Unit
Ciss input capacitance VDS = 15 V; f = 1 MHz
VGS = 10 V - 1.7 - pF
VGS = 0 V - 3 - pF
Crss reverse transfer capacitance VDS = 15 V; f = 1 MHz
VGS = 10 V - 0.8 - pF
VGS = 0 V - 0.9 - pF
gis common source input
conductance
VDS = 10 V; ID = 1 mA
f = 100 MHz - 15 - S
f = 450 MHz - 300 - S
gfs common source transfer
conductance
VDS = 10 V; ID = 1 mA
f = 100 MHz - 2 - mS
f = 450 MHz - 1.8 - mS
grs common source reverse
conductance
VDS = 10 V; ID = 1 mA
f = 100 MHz - 6 - S
f = 450 MHz - 40 - S
gos common source output
conductance
VDS = 10 V; ID = 1 mA
f = 100 MHz - 30 - S
f = 450 MHz - 60 - S
VDS = 15 V; Tj = 25 C. VDS = 15 V; VGS = 0 V; Tj = 25 C.
Fig 2. Drain current as a function of gate-source
cut-off voltage; typical values.
Fig 3. Forward transfer admittance as a function of
gate-source cut-off voltage; typical values.
VGSoff (V)
0 −8−6−2 −4
mbb467
10
20
30
IDSS
(mA)
0
VGSoff (V)
0 −8−6−2 −4
mbb466
5
4.5
5.5
6
Yfs
(mS)
4
BF545A_BF545B_BF545C All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 4 — 15 September 2011 6 of 16
NXP Semiconductors BF545A; BF545B; BF545C
N-channel silicon junction field-effect transistors)
VDS = 15 V; VGS = 0 V; Tj = 25 C. VDS = 100 mV; VGS = 0 V; Tj = 25 C.
Fig 4. Common-source output admittance as a
function of gate-source cut-off voltage; typical
values.
Fig 5. Drain-source on-resistance as a function of
gate-source cut-off voltage; typical values.
BF545A
Tj = 25 C.
(1) VGS = 0 V.
(2) VGS = 0.5 V.
(3) VGS = 1.0 V.
BF545A
VDS = 15 V; Tj = 25 C.
Fig 6. Typical output characteristics. Fig 7. Typical input characteristics.
VGSoff (V)
0 −8−6−2 −4
mbb465
40
20
60
80
Yos
(μS)
0
VGSoff (V)
0 −8−6−2 −4
mbb464
100
200
300
RDSon
(Ω)
0
VDS (V)
0 16124 8
mbb462
2
4
6
ID
(mA)
0
(1)
(2)
(3)
VGS (V)
−3 0−1−2
mbb463
2
4
6
ID
(mA)
0
BF545A_BF545B_BF545C All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 4 — 15 September 2011 7 of 16
NXP Semiconductors BF545A; BF545B; BF545C
N-channel silicon junction field-effect transistors)
BF545B
Tj = 25 C.
(1) VGS = 0 V.
(2) VGS = 0.5 V.
(3) VGS = 1.0 V.
(4) VGS = 1.5 V.
(5) VGS = 2.0 V.
(6) VGS = 2.5 V.
BF545B
VDS = 15 V; Tj = 25 C.
Fig 8. Typical output characteristics. Fig 9. Typical input characteristics.
VDS (V)
0 16124 8
mbb460
8
4
12
16
ID
(mA)
0
(1)
(6)
(2)
(3)
(4)
(5)
mbb459
VGS (V)
−6 0−2−4
8
4
12
16
ID
(mA)
0
BF545A_BF545B_BF545C All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 4 — 15 September 2011 8 of 16
NXP Semiconductors BF545A; BF545B; BF545C
N-channel silicon junction field-effect transistors)
BF545C
Tj = 25 C.
(1) VGS = 0 V.
(2) VGS = 1.0 V.
(3) VGS = 2.0 V.
(4) VGS = 3.0 V.
(5) VGS = 4.0 V.
(6) VGS = 5.0 V.
BF545C
VDS = 15 V; Tj = 25 C.
Fig 10. Typical output characteristics. Fig 11. Typical input characteristics.
VDS (V)
0 16124 8
mbb457
10
20
30
ID
(mA)
0
(1)
(2)
(3)
(4)
(5)
(6)
VGS (V)
−8 0−2−6 −4
mbb456
10
20
30
ID
(mA)
0
BF545A_BF545B_BF545C All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 4 — 15 September 2011 9 of 16
NXP Semiconductors BF545A; BF545B; BF545C
N-channel silicon junction field-effect transistors)
BF545A
VDS = 15 V; Tj = 25 C.
BF545B
VDS = 15 V; Tj = 25 C.
Fig 12. Drain current as a function of gate-source
voltage; typical values.
Fig 13. Drain current as a function of gate-source
voltage; typical values.
BF545C
VDS = 15 V; Tj = 25 C.
ID = 10 mA only for BF545B and BF545C; Tj = 25 C.
(1) ID = 10 mA.
(2) ID = 1 mA.
(3) ID = 0.1 mA.
(4) IGSS.
Fig 14. Drain current as a function of gate-source
voltage; typical values.
Fig 15. Gate current as a function of drain-gate
voltage; typical values.
mbb461
VGS (V)
−3 0−1−2
1
10−2
10−1
102
10
103
ID
(μA)
10−3
mbb458
VGS (V)
−6 0−2−4
1
10−2
10−1
102
10
103
ID
(μA)
10−3
mbb455
1
10−2
10−1
102
10
103
ID
(μA)
10−3
VGS (V)
−8 0−2−6 −4
mbb454
−10−1
−1
−10
−102
IG
(pA)
−10−2
VDG (V)
0 20168 124
(3)
(4)
(2)
(1)
BF545A_BF545B_BF545C All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 4 — 15 September 2011 10 of 16
NXP Semiconductors BF545A; BF545B; BF545C
N-channel silicon junction field-effect transistors)
VDS = 0 V; VGS = 20 V. VDS = 15 V; Tj = 25 C.
Fig 16. Gate current as a function of junction
temperature; typical values.
Fig 17. Reverse transfer capacitance as a function of
gate-source voltage; typical values.
VDS = 15 V; Tj = 25 C. VDS = 10 V; ID = 1 mA; Tamb = 25 C.
(1) bis.
(2) gis.
Fig 18. Typical input capacitance. Fig 19. Common-source input admittance; typical
values.
mbb453
−1
−10
−102
−103
IGSS
(pA)
10−1
Tj (°C)
−50 1501000 50
VGS (V)
−10 0−2−6 −4−8
mbb452
0.4
0.6
0.2
0.8
1
Crss
(pF)
0
VGS (V)
−10 0−2−6 −4−8
mbb451
1
2
3
Ciss
(pF)
0
mbb468
f (MHz)
10 103102
10−1
1
10
102
yis
(mS)
10−2
(1)
(2)
BF545A_BF545B_BF545C All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 4 — 15 September 2011 11 of 16
NXP Semiconductors BF545A; BF545B; BF545C
N-channel silicon junction field-effect transistors)
VDS = 10 V; ID = 1 mA; Tamb = 25 C.
(1) gfs.
(2) bfs.
VDS = 10 V; ID = 1 mA; Tamb = 25 C.
(1) brs.
(2) grs.
Fig 20. Common-source forward transfer admittance;
typical values.
Fig 21. Common-source reverse transfer admittance;
typical values.
VDS = 10 V; ID = 1 mA; Tamb = 25 C.
(1) bos.
(2) gos.
Fig 22. Common-source output admittance; typical values.
mbb469
10
1
102
Yfs
(mS)
10−1
f (MHz)
10 103102
(2)
(1)
mbb470
f (MHz)
10 103102
10−2
10−1
1
10
yrs
(mS)
10−3
(1)
(2)
mbb471
1
10−1
10
yos
(mS)
10−2
f (MHz)
10 103102
(1)
(2)
BF545A_BF545B_BF545C All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 4 — 15 September 2011 12 of 16
NXP Semiconductors BF545A; BF545B; BF545C
N-channel silicon junction field-effect transistors)
9. Package outline
Fig 23. Package outline.
UNIT
A1
max.
bp c D E e1 HE Lp Q wv
REFERENCESOUTLINE
VERSION
EUROPEAN
PROJECTION
ISSUE DATE
04-11-04
06-03-16
IEC JEDEC JEITA
mm 0.1
0.48
0.38
0.15
0.09
3.0
2.8
1.4
1.2
0.95
e
1.9
2.5
2.1
0.55
0.45
0.10.2
DIMENSIONS (mm are the original dimensions)
0.45
0.15
SOT23 TO-236AB
bp
D
e1
e
A
A1
Lp
Q
detail X
HE
E
w M
v M A
B
AB
0 1 2 mm
scale
A
1.1
0.9
c
X
1 2
3
Plastic surface-mounted package; 3 leads SOT23
BF545A_BF545B_BF545C All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 4 — 15 September 2011 13 of 16
NXP Semiconductors BF545A; BF545B; BF545C
N-channel silicon junction field-effect transistors)
10. Revision history
Table 9. Revision history
Document ID Release date Data sheet status Change notice Supersedes
BF545A_BF545B_BF545C v.4 20110915 Product data sheet - BF545A_BF545B_BF545C v.3
Modifications: • The format of this data sheet has been redesigned to comply with the new identity
guidelines of NXP Semiconductors.
• Legal texts have been adapted to the new company name where appropriate.
• Package outline drawings have been updated to the latest version.
BF545A_BF545B_BF545C v.3
(9397 750 13391)
20040805 Product data sheet - BF545A-B-C v.2
BF545A-B-C v.2 19960729 Product specification - -
BF545A_BF545B_BF545C All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 4 — 15 September 2011 14 of 16
NXP Semiconductors BF545A; BF545B; BF545C
N-channel silicon junction field-effect transistors)
11. Legal information
11.1 Data sheet status
[1] Please consult the most recently issued document before initiating or completing a design.
[2] The term ‘short data sheet’ is explained in section “Definitions”.
[3] The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status
information is available on the Internet at URL http://www.nxp.com.
11.2 Definitions
Draft — The document is a draft version only. The content is still under
internal review and subject to formal approval, which may result in
modifications or additions. NXP Semiconductors does not give any
representations or warranties as to the accuracy or completeness of
information included herein and shall have no liability for the consequences of
use of such information.
Short data sheet — A short data sheet is an extract from a full data sheet
with the same product type number(s) and title. A short data sheet is intended
for quick reference only and should not be relied upon to contain detailed and
full information. For detailed and full information see the relevant full data
sheet, which is available on request via the local NXP Semiconductors sales
office. In case of any inconsistency or conflict with the short data sheet, the
full data sheet shall prevail.
Product specification — The information and data provided in a Product
data sheet shall define the specification of the product as agreed between
NXP Semiconductors and its customer, unless NXP Semiconductors and
customer have explicitly agreed otherwise in writing. In no event however,
shall an agreement be valid in which the NXP Semiconductors product is
deemed to offer functions and qualities beyond those described in the
Product data sheet.
11.3 Disclaimers
Limited warranty and liability — Information in this document is believed to
be accurate and reliable. However, NXP Semiconductors does not give any
representations or warranties, expressed or implied, as to the accuracy or
completeness of such information and shall have no liability for the
consequences of use of such information.
In no event shall NXP Semiconductors be liable for any indirect, incidental,
punitive, special or consequential damages (including - without limitation - lost
profits, lost savings, business interruption, costs related to the removal or
replacement of any products or rework charges) whether or not such
damages are based on tort (including negligence), warranty, breach of
contract or any other legal theory.
Notwithstanding any damages that customer might incur for any reason
whatsoever, NXP Semiconductors’ aggregate and cumulative liability towards
customer for the products described herein shall be limited in accordance
with the Terms and conditions of commercial sale of NXP Semiconductors.
Right to make changes — NXP Semiconductors reserves the right to make
changes to information published in this document, including without
limitation specifications and product descriptions, at any time and without
notice. This document supersedes and replaces all information supplied prior
to the publication hereof.
Suitability for use — NXP Semiconductors products are not designed,
authorized or warranted to be suitable for use in life support, life-critical or
safety-critical systems or equipment, nor in applications where failure or
malfunction of an NXP Semiconductors product can reasonably be expected
to result in personal injury, death or severe property or environmental
damage. NXP Semiconductors accepts no liability for inclusion and/or use of
NXP Semiconductors products in such equipment or applications and
therefore such inclusion and/or use is at the customer’s own risk.
Applications — Applications that are described herein for any of these
products are for illustrative purposes only. NXP Semiconductors makes no
representation or warranty that such applications will be suitable for the
specified use without further testing or modification.
Customers are responsible for the design and operation of their applications
and products using NXP Semiconductors products, and NXP Semiconductors
accepts no liability for any assistance with applications or customer product
design. It is customer’s sole responsibility to determine whether the NXP
Semiconductors product is suitable and fit for the customer’s applications and
products planned, as well as for the planned application and use of
customer’s third party customer(s). Customers should provide appropriate
design and operating safeguards to minimize the risks associated with their
applications and products.
NXP Semiconductors does not accept any liability related to any default,
damage, costs or problem which is based on any weakness or default in the
customer’s applications or products, or the application or use by customer’s
third party customer(s). Customer is responsible for doing all necessary
testing for the customer’s applications and products using NXP
Semiconductors products in order to avoid a default of the applications and
the products or of the application or use by customer’s third party
customer(s). NXP does not accept any liability in this respect.
Limiting values — Stress above one or more limiting values (as defined in
the Absolute Maximum Ratings System of IEC 60134) will cause permanent
damage to the device. Limiting values are stress ratings only and (proper)
operation of the device at these or any other conditions above those given in
the Recommended operating conditions section (if present) or the
Characteristics sections of this document is not warranted. Constant or
repeated exposure to limiting values will permanently and irreversibly affect
the quality and reliability of the device.
Terms and conditions of commercial sale — NXP Semiconductors
products are sold subject to the general terms and conditions of commercial
sale, as published at http://www.nxp.com/profile/terms, unless otherwise
agreed in a valid written individual agreement. In case an individual
agreement is concluded only the terms and conditions of the respective
agreement shall apply. NXP Semiconductors hereby expressly objects to
applying the customer’s general terms and conditions with regard to the
purchase of NXP Semiconductors products by customer.
No offer to sell or license — Nothing in this document may be interpreted or
construed as an offer to sell products that is open for acceptance or the grant,
conveyance or implication of any license under any copyrights, patents or
other industrial or intellectual property rights.
Export control — This document as well as the item(s) described herein
may be subject to export control regulations. Export might require a prior
authorization from national authorities.
Document status[1][2] Product status[3] Definition
Objective [short] data sheet Development This document contains data from the objective specification for product development.
Preliminary [short] data sheet Qualification This document contains data from the preliminary specification.
Product [short] data sheet Production This document contains the product specification.
BF545A_BF545B_BF545C All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 4 — 15 September 2011 15 of 16
NXP Semiconductors BF545A; BF545B; BF545C
N-channel silicon junction field-effect transistors)
Quick reference data — The Quick reference data is an extract of the
product data given in the Limiting values and Characteristics sections of this
document, and as such is not complete, exhaustive or legally binding.
Non-automotive qualified products — Unless this data sheet expressly
states that this specific NXP Semiconductors product is automotive qualified,
the product is not suitable for automotive use. It is neither qualified nor tested
in accordance with automotive testing or application requirements. NXP
Semiconductors accepts no liability for inclusion and/or use of
non-automotive qualified products in automotive equipment or applications.
In the event that customer uses the product for design-in and use in
automotive applications to automotive specifications and standards, customer
(a) shall use the product without NXP Semiconductors’ warranty of the
product for such automotive applications, use and specifications, and (b)
whenever customer uses the product for automotive applications beyond
NXP Semiconductors’ specifications such use shall be solely at customer’s
own risk, and (c) customer fully indemnifies NXP Semiconductors for any
liability, damages or failed product claims resulting from customer design and
use of the product for automotive applications beyond NXP Semiconductors’
standard warranty and NXP Semiconductors’ product specifications.
11.4 Trademarks
Notice: All referenced brands, product names, service names and trademarks
are the property of their respective owners.
12. Contact information
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: salesaddresses@nxp.com
NXP Semiconductors BF545A; BF545B; BF545C
N-channel silicon junction field-effect transistors)
© NXP B.V. 2011. All rights reserved.
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: salesaddresses@nxp.com
Date of release: 15 September 2011
Document identifier: BF545A_BF545B_BF545C
Please be aware that important notices concerning this document and the product(s)
described herein, have been included in section ‘Legal information’.
13. Contents
1 Product profile . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 General description . . . . . . . . . . . . . . . . . . . . . 1
1.2 Features and benefits. . . . . . . . . . . . . . . . . . . . 1
1.3 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.4 Quick reference data . . . . . . . . . . . . . . . . . . . . 1
2 Pinning information. . . . . . . . . . . . . . . . . . . . . . 2
3 Ordering information. . . . . . . . . . . . . . . . . . . . . 2
4 Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
5 Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . . 3
6 Thermal characteristics . . . . . . . . . . . . . . . . . . 3
7 Static characteristics. . . . . . . . . . . . . . . . . . . . . 4
8 Dynamic characteristics . . . . . . . . . . . . . . . . . . 5
9 Package outline . . . . . . . . . . . . . . . . . . . . . . . . 12
10 Revision history. . . . . . . . . . . . . . . . . . . . . . . . 13
11 Legal information. . . . . . . . . . . . . . . . . . . . . . . 14
11.1 Data sheet status . . . . . . . . . . . . . . . . . . . . . . 14
11.2 Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
11.3 Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
11.4 Trademarks. . . . . . . . . . . . . . . . . . . . . . . . . . . 15
12 Contact information. . . . . . . . . . . . . . . . . . . . . 15
13 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16