Data Sheet

ADP1660

Rev. 0 | Page 15 of 28

FIXED 5 V OUTPUT MODE WITH TORCH

The ADP1660 can be used as a 5 V boost converter for a key-

pad LED driver voltage or an audio voltage rail (see Figure 27

and Figure 28). In this mode, the device supplies up to 500 mA

with torch currents available on the LED outputs.

To enable 5 V output voltage mode with torch currents,

1. Set the LED1_EN and LED2_EN bits in Register 0x0F to 0.

2. Enable the 5 V output by setting the LED_MOD bits (Bits[2:0]

in Register 0x01) to 110.

3. Enable the LED outputs by setting the LED1_EN and

LED2_EN bits to 1.

4. If desired, set the torch/assist currents for the LEDs using

Register 0x08 (for LED1) and Register 0x0B (for LED2).

These currents can be toggled with the GPIO (torch) pin.

If the LED is enabled and the GPIO (torch) pin is low, the

LED outputs low levels of current.

The VOUT pin is connected to the SW node when the

ADP1660 is not enabled. Do not connect VOUT directly to

a positive external voltage source; doing so causes current to

flow from VOUT to the battery.

ADP1660

10µF

1.0µH

PGND

SW

STROBE

10µF

LED1

EN

SGND

SCL

SDA

GPIO

OFF

ON

SDA, SCL

EN

APPLICATIONS PROCESSOR

3.2 MEGAPIXEL

TO 5.0 MEGAPIXEL

CMOS IMAGE SENSOR

POWER-ON RESET

VOUT = 5.0V

KEYPAD

LED DRIVER

VDD

GND

VOUT*

VIN

LED2

*THE VOUT PIN IS CONNECTED TO THE SW NODE WHEN THE ADP1660 IS NOT ENABLED. VOUT SHOULD NOT BE CONNECTED DIRECTLY TO A POSITIVE

EXTERNAL VOLTAGE SOURCE BECAUSE THIS WILL CAUSE CURRENT TO FLOW FROM VOUT TO THE BATTERY.

Figure 27. ADP1660 Voltage Regulation Mode: Keypad LED Driver Application

SHUTDOWN

VDD

OUT+

OUT–

IN+

GND

SD

AUDIO IN–

AUDIO IN+

SSM2315

80kΩ

80kΩ

160kΩ

160kΩ

BIAS

0.1µF

ADP1660

10µF

1.0µH

PGND

SW

STROBE

10µF

EN

SGND

SCL

SDA

GPIO

OFF

ON

SDA, SCL

EN

APPLICATIONS

PROCESSOR

3.2 MEGAPIXEL

TO 5.0 MEGAPIXEL

CMOS IMAGE SENSOR

POWER-ON

RESET

VOUT*

VIN

IN–

47nF

47nF

FET

DRIVER

POP/CLICK

SUPPRESSION

INTERNAL

OSCILLATOR

MODULATOR

(Σ-Δ)

LED1

LED2

*THE VOUT PIN IS CONNECTED TO THE SW NODE WHEN THE ADP1660 IS NOT ENABLED. VOUT SHOULD NOT BE CONNECTED DIRECTLY TO A POSITIVE

EXTERNAL VOLTAGE SOURCE BECAUSE THIS WILL CAUSE CURRENT TO FLOW FROM VOUT TO THE BATTERY.

Figure 28. ADP1660 Voltage Regulation Mode: Class-D Audio Application