Data Sheet

ADPD2210

Rev. A | Page 13 of 15

3-WIRE VOLTAGE CONFIGURATION

The ADPD2210 can be used in a minimal 3-wire voltage

configuration, offering a compact solution with very few

transimpedance gain in front of the analog-to-digital converter

(ADC). This configuration allows flexibility in matching the

ADC converter full-scale input to the full-scale output of the

ADPD2210. The dynamic range of the interface is limited to

the compliance voltage of the ADPD2210.

No additional amplification is needed prior to the ADC. Response

time at the lower end of the range is limited by the ability of the

output current to charge the parasitic capacitance presented to

the output of the ADPD2210.

3-WIRE CURRENT MODE CONFIGURATION

When used in the 3-wire current mode configuration with a

photodiode (see Figure 25), the ADPD2210 is insensitive to load

resistance and can be used when the signal processing is further

from the sensor. EMI noise and shielding requirements are

minimized; however, cable capacitance has a direct effect on

bandwidth, making the 3-wire current mode configuration a

chosen carefully to eliminate stability and bandwidth degrada-

tion of the ADPD2210. Large capacitance around the feedback

loop of the TIA has a direct effect on the bandwidth of the system.

Figure 25. ADPD2210 Used in 3-Wire Short Cable Voltage Mode Configuration with a Shunt Resistor

Figure 26. ADPD2210 Used in 3-Wire Current Mode Configuration with a TIA

ADPD2210

CURRENT

AMPLIFIER

REF

IN

ADC AND

MICROPROCESSOR

3.3V

3.3V

GND

OUT

VCC

VCC

OUT

GND

3.3V

TIA

3.3V

ADPD2210

CURRENT

AMPLIFIER

REF

IN

ADC AND

MICROPROCESSOR