SH3100 Datasheet, PDF (13/80 Pages) Semtech Corporation – Supervisory IC with I2C Interface and PWM

POWER MANAGEMENT
Application Diagrams - Modes 1 to 3
.
Mode 1 – Standard operation
No LDO, fan control or switching regulation.
General purpose PWM/PDM output is available
Use with or without external 32.768 kHz crystal
Register settings
DeviceMode = 000
Mode 2 – LDO enabled
As standard operation but with PWM output pin
programmed as LDO output. (Linearly regulated
down from VDD).
Register settings
DeviceMode = 100
ForcedDACValue = xx (to set LDO
voltage)
Mode 3 – Auto fan speed control
Fan speed is automatically controlled by measuring
temperature at regular intervals and adjusting PWM
duty cycle according to configurable control
parameters.
SNSE pin is monitored to detect possible fan stall
Register settings
DeviceMode = 101
ComparatorSource = 11 (SNSE)
CLK1HF/LF = 0
ForcedDACValue = xx (to override 70 mV
SNSE threshold if required)
© 2006 Semtech Corp.
13
SH3100
www.semtech.com