Introduction

The TLSR8258F512 embeds a low power comparator. This comparator takes two inputs:

input derived from external PortB:PB<1> ~ PB<7>
reference input derived from internal reference: PB<0>,PB<3>, AVDD3 or float.

Block diagram of Low Power Comparator

Comparison Principle

The low power comparator output is determined by the comparison result of the value of [input voltage * scaling] and reference voltage input. The comparison principle is shown as below:

[input voltage * scaling] > [reference voltage input]: 0
[input voltage * scaling] < [reference voltage input]: 1
[input voltage * scaling] == [reference voltage input] or input channel is float : uncertain

Normal Mode

In normal mode, the internal reference is derived from UVLO(Ultra-low Voltage Lockout) and has higher accuacy, but current bias is larger (10uA); reference voltage input channel is selectable from internal reference : 972mV,921mV,870mV and 819mV, as well as PB<0>, PB<3>, AVDD3 and float.

Low Power Mode

In low power mode, the internal reference is derived from Bandgap and has lower accuracy, but current bias is decreased to 50nA; reference voltage input channel is selectable from internal reference of 964mV, 913mV,862mV and 810mV,as well as PB<0>, PB<3>, AVDD3 and float.

LPC APIs List

In order to facilitate users to quickly develop products according to their own needs, TSI provide the following related APIs and examples.

APIs list	Description	Example	Update Date	Status
lpc_power_on()	power on Low power comparator, which is powered down by default	API-USB-CASE1	2019-1-10	Done
lpc_power_down()	power down Low power comparator	-	2019-1-10	Done
lpc_set_input_chn()	select the input channel	API-USB-CASE1	2019-1-10	Done
lpc_set_input_ref()	select the input reference	API-USB-CASE1	2019-1-10	Done
lpc_set_scaling_coeff()	set the scaling coefficient of the input channel	API-USB-CASE1	2019-1-10	Done
lpc_get_result()	set the scaling coefficient of the input channel	API-USB-CASE1	2019-1-10	Done

TSI provides the following examples of this module to help users quickly understand and apply related modules.

Examples list	Description	Update Date	Status
API-USB-CASE1	low power comparator in normal mode	2019-1-10	Done
API-USB-CASE2	low power comparator in low power mode	2019-1-10	Done

History Record

Date	Description	Author
2019-1-10	initial release	SP/LJW