Diodes AP2502 User Manual

4-CH Linear Constant Current Sink With Matching AP2502

Data Sheet

General Description

The AP2502 is a 4-channel independent linear
current sink with low dropout voltage and perfect
match between each channel. Each channel can
provide 20mA continuous constant current.

In application, there is only one 0.1µF ceramic
capacitor required, and there is no any EMI and
switching noise issue. It is perfect choice for
hand-hold portable system especially based on
Li-ion/Polymer battery power e d di spl ay module.

The brightness can be controlled and/or adjustable
via simple PWM signal applied to EN pin.

The AP2502 is available with SOT-23-6 and
TSOT-23-6 packages.

Features

• Current Matching Between Each Channel: ±1%

• Low Dropout Voltage: 65mV (Typ.) @ I
20mA

• Maximum Output Current on Each Channel:
20mA

• Ultra-low Quiescent Current: 125µA (Typ.)

• Ultra-low Shutdown Current: 1µA (Max.)

• None EMI and Switching Noise Issue

• Permitted PWM Dimming Frequency up to

• 150kHz

• OTSD Protection

LED

Applications

• Mobile Phone, Smart Phone, PDA

• MP3, MP4, PMP

• Small Size Backlight Module

SOT-23-6 TSOT-23-6

Figure 1. Package Types of AP2502

=

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Data Sheet

4-CH Linear Constant Current Sink With Matching AP2502

Pin Configuration

K/KT Package

(SOT-23-6/TSOT-23-6)

Figure 2. Pin Configuration of AP2502 (Top View)

Pin Descriptions

P in Number Pin Name Description

1 EN

2 GND GND

3, 4, 5, 6 LED4 to LED1 LED cathode terminal for channel number

Oct. 2010 Rev 1. 1 BCD Semiconductor Manufacturing Limited

Chip enable pin, active high to permit PWM signal input for brightness control by
changing duty cycle

2

Data Sheet

4-CH Linear Constant Current Sink With Matching AP2502

Functional Block Diagram

Figure 3. Functional Block Diagram of AP2502

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Data Sheet

4-CH Linear Constant Current Sink With Matching AP2502

Ordering Information

AP2502 -

Circuit Type G1: Green

Package
K: SOT-23-6
KT: TSOT-23-6

Package

SOT-23-6

TSOT-23-6

BCD Semiconductor's Pb-free products, as designated with "G1" suffix in the part number, are RoHS compliant

and Green.

Temperature

Range

-40 to 85°C

-40 to 85°C

Part Number Marking ID

AP2502KTR-G1 GEE Tape & Reel
AP2502KTTR-G1 L7E Tape & Reel

TR: Tape & Reel

Packing

Type

Absolute Maximum Ratings (Note 1)

Parameter Symbol Value Unit

Enable Input Voltage VEN -0.3 to 6.5 V
Thermal Resistance (Junction to Ambient)
Operating Junction Temperature Range TJ 150 ºC
Storage Temperature Range T

Lead Temperature (Soldering,10 seconds) T
ESD (Machine Model) 600 V

ESD (Human Body Model) 6000 V

θ

JA

-65 to 150 ºC

STG

260 ºC

LEAD

250 ºC/W

Note 1: Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to
the device. These are stress ratings only, and functional operation of the device at these or any other conditions
beyond those indicated under “Recommended Operating Conditions” is not implied. Exposure to “Absolute
Maximum Ratings” for extended periods may affect device reliability.

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k

Data Sheet

4-CH Linear Constant Current Sink With Matching AP2502

Recommended Operating Conditions

Parameter Symbol

Unit

Min Max

Value

Enable Input Voltage VEN 2.0 6.0 V
Operating Temperature Range TA -40 85 °C

Sink Current I

20 mA

LED

Electrical Characteristics

VIN=3.6V, V

Parameter Symbol Test Conditions Min Typ Max Unit

LED Dropout Voltage V

Enable PIN High Voltage VIH 2 6 V

=3.2V, TA = 25°C, unless otherwise specified.

F_LED

DROPOUT

I

=20mA 65 120 mV

SINK

Enable PIN Low Voltage VIL 0 0.5 V

LED Maximum Sin
Current

Sink Current Matching
Between each Chann el

I

LED(MAX)

I

LED-MATCH

Quiescent Current IQ I

Shutdown Current I

SHUTDOWN

Thermal Resistance (Junction
to Case)

PWM Frequency to Adjust
Brightness

EN Pin Pulse High Time T
EN Pin Pulse Low Time T

Thermal Shutdown
Temperature
Thermal Shutdown
Hysteresis

Oct. 2010 Rev 1. 1 BCD Semiconductor Manufacturing Limited

T

T

VCC=3.3 to 6.0V, Enable=VCC 18 20 22 mA

V

Set EN Pin Low 0.1 1

θ

JC

150 kHz

f

PWM

1

HIGH

100 ns

LOW

150

OTSD

=0.4V 0.5 1 %

LED

LED1=ILED2=ILED3=ILED4

=20mA 125 180

µA

µA

80

°C/W

µs

°C

25

HYOTSD

5

Data Sheet

4-CH Linear Constant Current Sink With Matching AP2502

Typical Performance Characteristics

200
190
180

Quiescent Current (µA)

LED Open

170

V

=3V

160
150
140
130
120
110
100

EN

90
80
70
60
50

-40 -20 0 20 40 60 80 100 120 140

Case Temperature (oC)

Figure 4. Quiescent Current vs. Case Temperature Figure 5. Quiescent Current vs. Enable Voltage

21.0

20.8

20.6

20.4

20.2

20.0

(mA)

19.8

LED

I

19.6

19.4

19.2

19.0

VEN=3V

=4V

V

IN

-40-200 20406080100120

Case Temperature (OC)

Figure 6. LED Current vs. Case Temperature Figure 7. LED Current vs. Output Voltage

Oct. 2010 Rev 1. 1 BCD Semiconductor Manufacturing Limited

200
190

LED Open

180
170
160
150
140
130
120
110
100

90

Quiescent Current (µA)

80
70
60

22
20
18
16
14
12
10

(mA)

LED

I

8
6
4
2
0

TC=-40oC
TC=25oC
TC=85oC

1234567

Enable Voltage (V)

VEN=3V

TC=-40oC
TC=25oC
TC=85oC

0 100 200 300 400 500 600 700 800 900 1000

Output Voltage (mV)

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Data Sheet

4-CH Linear Constant Current Sink With Matching AP2502

Typical Performance Characteristics (Continued)

120
110
100

90
80
70
60
50

Dropout Voltage (mV)

40
30
20

-40 -20 0 20 40 60 80 100 120 140

Case Temperature (oC)

Figure 8. Dropout Voltage vs. Case Temperature Figure 9. Current Matching vs. Case Temperature

24.0

23.5

23.0

22.5

22.0

21.5

21.0

20.5

20.0

(mA)

19.5

LED

I

19.0

18.5

18.0

17.5

17.0

16.5

16.0

2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0

Enable Voltage (V)

V

=300mV

LED

TC=25oC

Figure 10. LED Current vs. Enable Voltage Figure 11. LED Current Efficiency vs. Duty Cycle

1.0

0.8

0.6

0.4

0.2

0.0

-0.2

-0.4

Current Matching (%)

-0.6

-0.8

-1.0

-40 -20 0 20 40 60 80 100 120 140

Case Temperature (oC)

110
100

90
80
70
60
50
40
30
20

LED Current Efficiency (%)

10

0

-10
0 102030405060708090

Duty Cycle (%)

T

C

VEN=3V
V

=25oC

=300mV

LED

f=100Hz
f=10kHz
f=100kHz
f=150kHz

99

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Data Sheet

4-CH Linear Constant Current Sink With Matching AP2502

Typical Performance Characteristics (Continued)

VEN

2V/div

10mA/div

I

LED

I1 I

2

2V/div

10mA/div

V

I

EN

LED

Time 400µs/div

Time 2ms/div

Figure 12. LED Current (Note 2) Figure 13. Internal Oscillator Working at Low Frequency
(VIN=4V, VEN=0 to 3.6V, Duty cycle=50%, f

Note 2: Chopper offset-canceling technology is adopted to ge t good current matching, I

=1kHz) (VIN=4V, VEN=0 to 3.6V, Duty cycle=50%, f

PWM

=[(I1+I2)/2]*duty.

LED

=0.1kHz)

PWM

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Data Sheet

4-CH Linear Constant Current Sink With Matching AP2502

Typical Application

Figure 14. AP2502 Typical Application

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Data Sheet

4-CH Linear Constant Current Sink With Matching AP2502

Mechanical Dimensions

SOT-23-6 Unit: mm(inch)

0°
8°

0.200(0.008)

0.300(0.012)

0.400(0.016)

6

2.820(0.111)

3.020(0.119)

5

0.300(0.012)

0.600(0.024)

4

Pin 1 Dot by Marking

123

0.950(0.037)TYP

1.800(0.071)

2.000(0.079)

0.700(0.028)REF

0.000(0.000)

0.150(0.006)

0.900(0.035)

1.300(0.051)

0.100(0.004)

0.200(0.008)

1.450(0.057)
MAX

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Data Sheet

4-CH Linear Constant Current Sink With Matching AP2502

Mechanical Dimensions (Continued)

TSOT-23-6 Unit: mm(inch)

°

2.800(0.110)

3.000(0.118)

R0.100(0.004)

MIN

0
8

°

1.500(0.059)

1.700(0.067)

0.950(0.037)
BSC

0.000(0.000)

0.100(0.004)

0.700(0.028)

0.900(0.035)

Pin 1 Dot by

Marking

1.900(0.075)
BSC

0.350(0.014)

0.510(0.020)

2.600(0.102)

3.000(0.118)

1.000(0.039)
MAX

GAUGE

PLANE

0.370(0.015)
MIN

0.100(0.004)

0.250(0.010)

0.250(0.010)
BSC

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BCD Semiconductor Manufacturing Limited

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IMPORTANT NOTICE

BCD Semiconductor Manufacturing Limited reserves the right to make changes without further notice to any products or specifi-

BCD Semiconductor Manufacturing Limited reserves the right to make changes without further notice to any products or specifi-

cations herein. BCD Semiconductor Manufacturing Limited does not assume any responsibility for use of any its products for any

cations herein. BCD Semiconductor Manufacturing Limited does not assume any responsibility for use of any its products for any

particular purpose, nor does BCD Semiconductor Manufacturing Limited assume any liability arising out of the application or use

particular purpose, nor does BCD Semiconductor Manufacturing Limited assume any liability arising out of the application or use

of any its products or circuits. BCD Semiconductor Manufacturing Limited does not convey any license under its patent rights or

of any its products or circuits. BCD Semiconductor Manufacturing Limited does not convey any license under its patent rights or

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