UCD3138128APFC datasheet(43/83 Pages) TI1

43 / 83 page

Vdd

I BIAS

To ADC Mux

On/Off Control

AD00,

AD01

Resistor to

set PMBus

Address

UCD3138128A

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SLUSC99 – JULY 2016

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9.3.7.2.1

Example: PMBus Address Decode via ADC12 Reading

The user can allocate 2 pins of the 12-bit ADC input channels, AD_00 and AD_01, for PMBus address decoding.

At power-up the device applies IBIAS to each address detect pin and the voltage on that pin is captured by the

internal 12-bit ADC.

Figure 30. PMBUS Address Detection Method

PMBus/I2C address 0x7E is a reserved address and should not be used in a system using the UCD3138xA. This

address is used for manufacturing test.

9.3.7.3 SPI

The SPI is a high-speed synchronous serial input/output port that allows a serial bit stream of programmed length

(1 to 16 bits) to be shifted into and out of the device at a programmed bit-transfer rate. The SPI is normally used

for communication between the UCD3138xA and external peripherals. Typical applications include an interface to

external I/O or peripheral expansion via devices such as shift registers, display drivers, SPI EPROMs and

analog-to-digital converters. The SPI allows serial communication with other SPI devices through a 3-pin or 4-pin

mode interface. A typical use case of SPI is to be configured as a master for communicating to external

EEPROM.

UCD3138128APFC Datasheet(PDF) 43 Page - Texas Instruments