Diodes AP3608E - Manual (Page 3)

EIGHT-CHANNEL CONSTANT CURRENT SINK WITH CURRENT MATCH AP3608E
Data Sheet
3
Mar. 2011 Rev. 1. 5 BCD Semiconductor Manufacturing Limited
Pin Number
Pin Name Function
QFN-4 × 4-24
TSSOP-20(EDP)/
SOIC-20
1, 24, 23, 22,
20, 19, 18, 17
1, 2, 3, 4, 7, 8, 9, 10 CH1to CH8 White LED cathode connection pin. These pins should be connected to
GND if not used
2 ,3 ,4, 6, 7, 13 12 NC No connection
5 11 PWM
PWM dimming control pin. Adding a PWM signal to this pin to control
LED dimming (see Figure 10 for detail dimming control mode). If not
used, connect it to the high level
8 13 FBX
This pin is an interface terminal. Connecting it with FB pin can achieve
parallel application. If not used, leave it unconnected
9 14 ISET
LED current set pin. An external resistor is connected to this pin to set
each channel current according to I
CHANNEL
=1.194*400/R
ISET
10 15 FB
Feedback pin. This pin is an interface terminal, which samples the volt-
age of each channel, and outputs the lowest voltage of the string to DC/
DC converter
11 16 SDB
This pin is an interface terminal. SDB pin outputs low logic to DC/DC
converter under the conditions such as AP3608E receives shutdown sig-
nal from EN pin or all channels are inactive. When AP3608E is on
PWM dimming mode, the signal in SDB pin is synchoronous with PWM
signal
12 17 SDBX
This pin is an interface terminal. Connecting it with SDB pin can
achieve parallel application. If not used, connect it to GND
14 18 AGND
Ground pin. It would be useful when connected with PGND and
exposed pad
15 19 VCC Input voltage pin
16 20 EN Enable pin. Logic high enables the IC and logic low disables the IC
21 5, 6 PGND
Ground pin. It would be useful when connected with AGND and
exposed pad
EP
Exposed pad. It would be useful when connected with AGND and
PGND
Pin Description