STPM01FTR datasheet(21/56 Pages) STMICROELECTRONICS

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STPM01

Theory of operation

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A BandGap voltage reference (VBG) of 1.23V ±1% is used as reference voltage level source

for the two linear regulators and for the A/D converters. Also, this module produces several

bias currents and voltages for all other analog modules and for the OTP module. The

bandgap voltage can be compensated regardless to the temperature variations with the

BGTC bits..

8.8

Load monitoring

The STPM01 includes a no load condition detection circuit with adjustable threshold. This

circuit monitors the voltage and the current channels and, when the measured voltage is

below the set threshold, the internal signal BIL becomes high. The information about this

signal is also available in the status bit BIL.

The no load condition occurs when the product between VRMS and IRMS register values is

below a given value. This value can be set with the LTCH configuration bits.

Four different no-load threshold values can be chosen according to the two configuration

bits LTCH (see table 11).

When a no load condition occurs (BIL=1) the integration of power is suspended and the

tamper module is disabled.

In standalone mode, if a no load condition is detected, the BIL signal blocks generation of

pulses for stepper and forces SCLNLC pin to be low. If APL=2 (see 8.14) the LED pin

continues providing the high frequency pulses, while if APL=3, the pulses are stopped as

happens for MOP and MON.

In peripheral mode, the BIL signal can be accessed only through the SPI interface.

Figure 17.

Bandgap temperature variation

Table 11.

No load detection thresholds

LTCH

KLTCH

0800

11600

23200

36400

STPM01FTR Datasheet(PDF) 21 Page - STMicroelectronics