ADP1650ACBZ-R7 datasheet(16/32 Pages) AD

16 / 32 page

ADP1650

Rev. 0 | Page 16 of 32

LED VF Mode

The ADC can measure the LED VF in both flash and assist/

torch modes. In torch mode, set ADC_EN = 01 to begin a

conversion. The value can be read back from the ADC_VAL[5:2]

bits 1 ms after the conversion has started. Assist/torch mode,

rather than flash mode, is best in the handset production test to

verify the LED VF.

REG 0x08, ADC_EN > 0

START CONVERSION

(INTERNAL SIGNAL)

1ms

ADC_VAL[5:2]

AVAILABLE FOR READ

I2C DATA BUS

Figure 36. ADC Timing for All Modes Except VF Measurement in Flash Mode

In flash mode, set ADC_EN = 01. The conversion happens just

before the timeout occurs; therefore, the FL_TIM bits set when

the ADC sample occurs. This allows the VF to settle from the

initial peak as the junction temperature of the LED stabilizes.

An LED temperature vs. flash time profile for the handset PCB

design can be generated during the design phase by varying the

FL_TIM bits from the lowest to the highest setting and collecting a

VF sample on each flash.

LED CURRENT

REG 0x02, FL_TIM = XXXX ms

REG 0x03, I_FL = XXXXX mA

REG 0x04, OUTPUT_EN = 1

STR_LV = 0

LED_MOD = 11

I2C DATA BUS

I(FLASH)

STROBE

FL_TIM

START CONVERSION

(INTERNAL SIGNAL)

ADC_VAL[5:2]

AVAILABLE FOR READ

REG 0x08, ADC_EN = 01

tS = 1ms

Figure 37. ADC Timing for VF Measurement in Flash Mode

Die Temperature Mode

The ADC measures the IC die temperature and provides the

result to the I2C interface. This is useful during the design phase

of the flash system to optimize PCB layout for the best thermal

design.

Write ADC_EN = 10 to begin a die temperature measurement.

The value can be read back from the ADC_VAL[5:2] bits 1 ms

after the conversion has started. The most stable and accurate

value of die temperature is available at the end of the flash pulse.

External Voltage Mode

The ADC measures the voltage on the GPIO2 pin when the

GPIO2 is configured as an ADC input by setting IO2_CFG =

11. One example is using an external temperature-dependent

resistor to create a voltage based on the temperature of the flash

LED. The EN line can be used for biasing to reduce leakage

current when the flash is not being used.

ADP1650ACBZ-R7 数据表(PDF) 16 Page - Analog Devices

ADP1650ACBZ-R7 数据表(HTML) 16 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

数据表下载