PSSI2021SAY,115 - NXP

1. Product proﬁle

1.1 General description

Resistor-equipped PNP transistor with two diodes on one chip in a SOT353 (SC-88A)

plastic package. Stabilized output current of between 15 µA and 50 mA by connection of

an external resistor between pins 4 and 5.

1.2 Features

nOne chip integrated constant current source

nOutput current setting by use of an external resistor

nVery small package

nReduces component count and board space

1.3 Applications

nAutomotive applications

nGeneric constant current source

nConstant current LED driver

nActive bias control for audio ampliﬁers

1.4 Quick reference data

PSSI2021SAY

Constant current source in SOT353 package

Rev. 03 — 27 August 2009 Product data sheet

Table 1. Quick reference data

Symbol Parameter Conditions Min Typ Max Unit

Iout output current 0.015 - 50 mA

VSsupply voltage - - 75 V

Product data sheet Rev. 03 — 27 August 2009 2 of 12

NXP Semiconductors PSSI2021SAY

Constant current source in SOT353 package

2. Pinning information

3. Ordering information

4. Marking

[1] * = -: made in Hong Kong

* = t: made in Malaysia

* = W: made in China

Table 2. Pinning

Pin Symbol Description Simpliﬁed outline Symbol

1 n.c. not connected

2 IOUT output current

3 GND ground

4 REXT external resistor

5 VS supply voltage 132

n.c.

sym049

Table 3. Ordering information

Type number Package

Name Description Version

PSSI2021SAY SC-88A plastic surface mounted package; 5 leads SOT353

Table 4. Marking codes

Type number Marking code[1]

PSSI2021SAY S1*

Product data sheet Rev. 03 — 27 August 2009 3 of 12

NXP Semiconductors PSSI2021SAY

Constant current source in SOT353 package

5. Limiting values

[1] Between all terminals

[2] Device mounted on a FR4 printed-circuit board, single-sided copper, tin-plated, standard footprint

6. Thermal characteristics

[1] Device mounted on a FR4 printed-circuit board, single-sided copper, tin-plated, standard footprint

7. Characteristics

Table 5. Limiting values

In accordance with the Absolute Maximum Rating System (IEC 60134).

Symbol Parameter Conditions Min Max Unit

Iout stabilized output current see Figure 2 0.015 50 mA

VSsupply voltage - 75 V

Vout output voltage VS = 75 V - 73 V

VRreverse voltage [1] - 0.5 V

Ptot total power dissipation Tamb ≤25 °C[2] - 335 mW

Tstg storage temperature −65 +150 °C

Tjjunction temperature - 150 °C

Tamb ambient temperature −65 +150 °C

Table 6. Thermal characteristics

Symbol Parameter Conditions Min Typ Max Unit

Rth(j-a) thermal resistance from

junction to ambient in free air [1] - - 370 K/W

Table 7. Characteristics

amb

= 25

C unless otherwise speciﬁed

Symbol Parameter Conditions Min Typ Max Unit

Iout stabilized output current VS=12V; R

ext = open;

Vout = 0 V to 10 V;

see Figure 2

10 15 20 µA

ISsupply current VS=12V; I

out =15µA;

Vout = 0 V to 10 V;

see Figure 4

- 240 370 µA

VS=75V; I

out =15µA;

Vout = 0 V; see Figure 4 - 1.5 2.2 mA

∆Iout / (Iout ×∆Tamb) output current change over

ambient temperature VS=12V; V

out =1V;

Tamb =−55 °C to 150 °C- 0.15 - %/K

∆Iout / Iout load stability of stabilized

output current VS=12 V;

Vout =1 V to 10 V - 0.5 - %

Rint internal resistor value - 48 - kΩ

Product data sheet Rev. 03 — 27 August 2009 4 of 12

NXP Semiconductors PSSI2021SAY

Constant current source in SOT353 package

VS= 12 V

(1) Iout = 20 mA

(2) Iout = 10 mA

(3) Iout = 1mA

(4) Iout = 100 µA

(5) Iout = 50 µA

(6) Iout = 15 µA

(1) Iout = 20 mA

(2) Iout = 10 mA

(3) Iout = 1mA

(4) Iout = 100 µA

(5) Iout = 50 µA

(6) Iout = 15 µA

Fig 1. Output current as a function of load

resistance; typical values Fig 2. Output current as a function of supply voltage;

typical values

VS= 12 V; RL= 100 ΩRext =∞; RL= 100 Ω

Fig 3. Output current as a function of external

resistance; typical values Fig 4. Supply current as a function of supply voltage;

typical values

006aaa020

RL (Ω)

10 104

103

102

10−1

102

Iout

(mA)

10−2

(1)

(2)

(3)

(4)

(5)

(6)

006aaa021

VS (V)

0806020 40

10−1

102

Iout

(mA)

10−2

(1)

(2)

(3)

(4)

(5)

(6)

006aaa022

Rext (Ω)

10 106

105

102104

103

10−1

102

Iout

(mA)

10−2

VS (V)

0806020 40

006aaa023

1.0

0.5

1.5

2.0

(mA)

Product data sheet Rev. 03 — 27 August 2009 5 of 12

NXP Semiconductors PSSI2021SAY

Constant current source in SOT353 package

8. Application information

External resistor calculation

The output current can be set by connecting an external resistor between VS (pin 5) and

REXT (pin 4).

Iout then calculates to:

Without an external resistor the output current will be typically 15 µA.

Typical output currents versus supply voltage VS

The applied supply voltage determines the output current. Table 8 gives typical Iout values

at speciﬁed supply voltages, assuming that the working output current is 70% of the

maximum possible output current.

Table 8. Typical output currents at speciﬁed supply voltages

VS (V) Iout (mA)

12 18

24 38

36 60

Iout 0.617

Rext

------------- 15 µA+=

Product data sheet Rev. 03 — 27 August 2009 6 of 12

NXP Semiconductors PSSI2021SAY

Constant current source in SOT353 package

8.1 Typical application circuits

LED driver

Figure 5 shows a typical application circuit for an LED driver. The constant current

ensures a constant LED brightness.

Switching the current ON/OFF

The output can be switched ON and OFF by connecting a resistor-equipped transistor

(RET, e.g. PDTC124XU) as shown in Figure 6.

Fig 5. LED driver application diagram

Fig 6. Switching the current ON/OFF; application diagram

006aaa024

VCC

Rext

REXT

IOUT Iout

LED

GND

006aaa025

IN/

OUT

VCC

Rext

REXT

IOUT

Iout

LED

GND

OUT

Product data sheet Rev. 03 — 27 August 2009 7 of 12

NXP Semiconductors PSSI2021SAY

Constant current source in SOT353 package

Voltage reference

The PSSI2021SAY supplies a constant current to the Zener diode regardless of supply

voltage variation, resulting in a constant reference voltage (see Figure 7).

Fig 7. Voltage reference application diagram

Vref

006aaa026

VCC

Rext

REXT

IOUT

Iout

GND

Product data sheet Rev. 03 — 27 August 2009 8 of 12

NXP Semiconductors PSSI2021SAY

Constant current source in SOT353 package

9. Package outline

Fig 8. Package outline SOT353 (SC-88A)

REFERENCES

OUTLINE

VERSION EUROPEAN

PROJECTION ISSUE DATE

IEC JEDEC JEITA

SOT353

wBM

detail X

vMA

0 1 2 mm

scale

132

Plastic surface-mounted package; 5 leads SOT353

UNIT A1

max bpcD

E (2) e1HELpQywv

mm 0.1 0.3

0.2 2.2

1.8

0.25

0.10 1.35

1.15 0.65

1.3 2.2

2.0 0.2 0.10.2

DIMENSIONS (mm are the original dimensions)

0.45

0.15 0.25

0.15

1.1

0.8

04-11-16

06-03-16

SC-88A

Product data sheet Rev. 03 — 27 August 2009 9 of 12

NXP Semiconductors PSSI2021SAY

Constant current source in SOT353 package

10. Packing information

[1] For further information and the availability of packing methods, see Section 13.

Table 9. Packing methods

The indicated -xxx are the last three digits of the 12NC ordering code.

[1]

Type number Package Description Packing quantity

3000

PSSI2021SAY SOT353 4 mm pitch, 8 mm tape and reel -115

Product data sheet Rev. 03 — 27 August 2009 10 of 12

NXP Semiconductors PSSI2021SAY

Constant current source in SOT353 package

11. Revision history

Table 10. Revision history

Document ID Release date Data sheet status Change notice Supersedes

PSSI2021SAY_3 20090827 Product data sheet - PSSI2021SAY_2

Modiﬁcations: •This data sheet was changed to reﬂect the new company name NXP Semiconductors,

including new legal deﬁnitions and disclaimers. No changes were made to the technical

content.

•Table 2 “Pinning”: amended

•Figure 8 “Package outline SOT353 (SC-88A)”: updated

PSSI2021SAY_2 20041020 Product data sheet - PSSI2021SAY_1

PSSI2021SAY_1 20010507 Product speciﬁcation - -

Product data sheet Rev. 03 — 27 August 2009 11 of 12

NXP Semiconductors PSSI2021SAY

Constant current source in SOT353 package

12. Legal information

12.1 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.

12.2 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.

12.3 Disclaimers

General — 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.

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 medical, military, aircraft,

space or life support 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.

Limiting values — Stress above one or more limiting values (as deﬁned in

the Absolute Maximum Ratings System of IEC 60134) may cause permanent

damage to the device. Limiting values are stress ratings only and operation of

the device at these or any other conditions above those given in the

Characteristics sections of this document is not implied. Exposure to limiting

values for extended periods may affect device reliability.

Terms and conditions of 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, including those pertaining to warranty,

intellectual property rights infringement and limitation of liability, unless

explicitly otherwise agreed to in writing by NXP Semiconductors. In case of

any inconsistency or conﬂict between information in this document and such

terms and conditions, the latter will prevail.

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.

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.

12.4 Trademarks

Notice: All referenced brands, product names, service names and trademarks

are the property of their respective owners.

13. Contact information

For more information, please visit: http://www.nxp.com

For sales ofﬁce addresses, please send an email to: salesaddresses@nxp.com

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.

NXP Semiconductors PSSI2021SAY

Constant current source in SOT353 package

For more information, please visit: http://www.nxp.com

For sales office addresses, please send an email to: salesaddresses@nxp.com

Date of release: 27 August 2009

Document identifier: PSSI2021SAY_3

Please be aware that important notices concerning this document and the product(s)

described herein, have been included in section ‘Legal information’.

14. Contents

1 Product proﬁle . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.1 General description. . . . . . . . . . . . . . . . . . . . . . 1

1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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 Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . 3

8 Application information. . . . . . . . . . . . . . . . . . . 5

8.1 Typical application circuits . . . . . . . . . . . . . . . . 6

9 Package outline . . . . . . . . . . . . . . . . . . . . . . . . . 8

10 Packing information. . . . . . . . . . . . . . . . . . . . . . 9

11 Revision history. . . . . . . . . . . . . . . . . . . . . . . . 10

12 Legal information. . . . . . . . . . . . . . . . . . . . . . . 11

12.1 Data sheet status . . . . . . . . . . . . . . . . . . . . . . 11

12.2 Deﬁnitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

12.3 Disclaimers. . . . . . . . . . . . . . . . . . . . . . . . . . . 11

12.4 Trademarks. . . . . . . . . . . . . . . . . . . . . . . . . . . 11

13 Contact information. . . . . . . . . . . . . . . . . . . . . 11

14 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12