4.1.6

FLT

FLT is an open-drain output that is asserted low when a fault is detected, after that a proper filter time is elapsed

(depending on the fault type). Fault pin cannot be asserted if WAKE pin voltage is below turn off threshold.

Table 13. FLT parameters

Symbol

Parameter

Test condition

Min

Typ

Max

Unit

Note

FLT_OD_LL

FLT_OD low level

Pull-up current = 1 mA

-

-

0.4

V

FLT

FLT_OD_Leakage

FLT_OD leakage

Apply 5 V to FLT, output buffer off

-

-

10

μA

FLT

4.1.7

Charge pump

The charge pump supplies the voltage necessary to drive the external N-channel MOSFETs. Average current

capability for the charge pump can guarantee proper turn on and turn off timings for oring MOSFET also in case

of AC ripple on the supply line (standard ISO 16750).

The charge pump is enabled immediately at the device power-up, once the battery level is higher than under-

voltage threshold, and WAKE input is high.

In case of under voltage on the charge pump (CP_UV), it is not possible to drive in the proper way the external

MOSFETs; the pre-drivers are therefore switched OFF and FLT pin is asserted low.

The same check on CP voltage is done during the power-up. Once CP_UV is released, device can complete the

power-up sequence. If CP_UV is not released by CP_UV_TIMEOUT expiration, drivers are turned off and FLT is

asserted.

Figure 8. Charge pump configuration simplified block diagram

Table 14. Charge pump parameters

Symbol

Parameter

Test condition

Min Typ Max Unit

PIN

VCP

Charge pump voltage

VB = 14 V, value referred to VB

(voltage above VB)

9

11.8

15

V

CPTANK

VCP_low

Charge pump voltage

VB = 4.5 V, value referred to VB

(voltage above VB)

5

-

-

V

CPTANK

CP_UV_L

Charge pump

Undervoltage_L

CPTANK pin falls from VB + 11 V

to VB + 0, Value referred to VB

(voltage above VB)

4

-

5

V

CPTANK

CP_UV_H

Charge pump

Undervoltage_H

CPTANK pin rises from VB + 0 to

VB + 11 V, Value referred to VB

(voltage above VB)

4.5

-

5.5

V

CPTANK

STPM801

Functional behavior in detail

DS13990 - Rev 2

page 16/38