TSM114

Housekeeping IC

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Housekeeping IC

TSM114 is a one chip solution for all PC SMPS: it

integrates on one chip the Housekeeping Circuitry

(Over Voltage and Under Voltage protections,

with adequate sequencing).

Multiple Power Line Protection

The TSM114 Housekeeping Circuit is dedicated

to 3.3V, 5V and

integrates a Precision Voltage Reference, a

multiple Over Voltage Protection Circuit and a

multiple Under Voltage Protection Circuit as well

as all the necessary logic and transient timing

management circuits for optimal and secure

communication with the motherboard, during start

up, switch off and stabilized conditions.

Over Voltage Protection

The Over Voltage Protection Circuit is made of

comparators with internal voltage thresholds

which do not require any external components for

proper

operation.

The

outputs

of

these

comparators are ORed.

Under Voltage Protection

The Under Voltage Protection Circuit is made of

comparators with internal voltage thresholds

which do not require any external components for

proper

operation.

The

outputs

of

these

comparators are ORed, and blanked by an

internal delay circuitry (Power Up Blanking - Tuv)

which can be adjusted with an external capacitor

(Cuv). This allows that during power up, the under

voltage protection circuit is inhibited.

Fault

The Over Voltage and Under Voltage Circuits

outputs are ORed before activating a latch. When

activated, this latch commands the full switch OFF

of the main power lines (3.3V, 5V, 12V) by an

external link between the housekeeping and the

primary PWM circuits via the main optocoupler or

any other device.

Power Good

The Under Voltage Circuits are Ored to switch the

Power Good output active (PG) to warn the

motherboard that the voltage of at least one of the

three power lines is out of range. The PG

activation bears an internal Tpg delay circuitry

which can be adjusted with an external capacitor

(Cpg).

Remote Control

Thanks to this information link to the motherboard,

a resetting signal to the latch is achievable with

the Remote pin (REM). When the Remote pin is

active,

the

external

Fault

link

between

Housekeeping circuit and the PWM generator is

active (high = PWM OFF) and the PG pin is active

(high). Note that to reset effectively the latch, a

minimum width Remote pulse should be applied

thanks to an internal delay circuitry (Trem) which

can be adjusted with an external capacitor

(Crem).