Datasheet

CODE = INT

x [2212.5 - 13.45(T - 30) - 0.005(T - 30)

] x 10

-3

4096

VREF

DAC Core x

CDAC OFFOLVL

OUTx

Device Pin

VDD

pin:Cy

CDAC:OFF

LMP92001

SNAS507B –FEBRUARY 2011–REVISED APRIL 2012

www.ti.com

Figure 19. Asynchronous Output Control

Note that CDAC.OFF affects all OUTx, whereas Cy affects only channels assigned to it. The correspondence

between Cy control inputs and OUTx outputs is governed by the CDAC.GANG bit and is outlined in Table 1.

Table 1. Cy to OUTx Assignment

Device Pin Cy CDAC:GANG = 0 CDAC:GANG = 1

C1 OUT[1:4] OUT[1:3]

C2 OUT[5:6] OUT[4:6]

C3 OUT[7:8] OUT[7:9]

C4 OUT[9:12] OUT[10:12]

TEMPERATURE SENSOR

The output voltage of the analog temperature sensor can be sampled via ADC channel 17 input. The result of

conversion is stored in the ADC17 register.

Typical ADC output code as a function of temperature:

In the expression above VREF is the reference input voltage to the internal ADC.

For best temperature measurement accuracy the exposed DAP of the device should be soldered to the PCB's

grounded pad, and the power dissipation of the device should be limited.

ADC/DAC VOLTAGE REFERENCE

The on-board ADC and DACs require reference voltages for their operation. By default the device is configured

to accept external references applied to AREF and DREF pins respectively. In this configuration AREF and

DREF can be at different potentials.

The external reference voltage sources should be bypassed to ground with capacitance appropriate for those

particular sources. See example application schematic in Application Circuit Example.

The device also has a built in precision reference block which can be used to provide VREF potential to either

ADC or DACs, or both at once. The internal buffers are designed to provide necessary drive to ADC and DAC

blocks. The internal reference buffers are not intended to drive external loads.

When internal reference is enabled the capacitance at AREF or DREF pins should be limited to 50 pF.

The functional diagram of the reference selector is shown in Figure 20.

Product Folder Links: LMP92001