L5965 datasheet(22/73 Pages) STMICROELECTRONICS

22 / 73 page

4.2.6

BOOST

The BOOST regulator is a converter running at 2.4 MHz that provides a nominal voltage of 5 V/7 V (selectable via

OTP). Spread Spectrum on PWM is enabled by default and disabled via SPI; a phase shift of 270° versus BUCK1

is internally generated. Soft start time is programmed via SPI. Compensation network is internal.

The BOOST regulator provides the following diagnostic:

•

Monitor of the output voltage by an independent circuit for UV/OV detection.

•

Monitor of the Power Good: thresholds status provided via SPI bit.

•

Over Current Protection.

•

Over Temperature detection by a local thermal sensor.

•

PGND5 loss detection.

BOOST fault management:

•

If a UV/OV fault occurs the FAULT pin is asserted and the fault bit is set in the SPI register, where it can be

read and cleared.

•

If OT occurs, the power stage is switched OFF with a 16 µs filter time. The output decreases until UV is

detected. The regulator goes in REC state and can restart only when OT flag is reset. The corresponding

SPI bit is set and FAULT pin is asserted.

•

The over current limitation is a cycle by cycle protection: when the fault happens, the corresponding fault

bit (Buck_OC_STAT) is set in the SPI register. This bit doesn't change the regulator behavior. If the fault

happens for 7 consequent cycles, the FAULT pin is asserted (latched).

•

If PGND5 ground loss occurs, the BOOST is turned OFF and FAULT pin is asserted. Until the fault is

present and stored any tentative of turning on the regulator is ignored. The BOOST can be turned on again

after the fault removal, and a Read & Clear cycle.

If this regulator is disabled and not used, VBOOST_S and PGND5 pins should be connected to ground.

4.2.7

LDO

LDO is a low drop out linear regulator with 8 programmable output voltages (5.0 V, 3.3 V, 2.8 V, 2.5 V, 1.8 V, 1.3 V,

1.25 V or 1.2 V) through OTP cell. The input voltage (VSLDO) is compatible to main regulator output (up to 5.5 V).

The LDO regulator provides the following diagnostic:

•

Programmable Over Current limitation in case of over-load or short to ground.

•

Monitor of the output voltage is monitored by an independent circuit for UV/OV detection.

•

Over Temperature detection by a local thermal sensor.

LDO Fault management:

•

In case of OV, the power stage is turned off, the fault SPI bit is set and the FAULT pin is asserted. The

power stage is turned on again when the OV is removed. RESET_B is asserted if enabled by OTP, and it

moves the device to REC state.

•

In case of UV, the SPI bit is set and the FAULT pin is asserted. RESET_B is asserted, according to OTP

reset activation and power up sequence, and moves the device to REC state.

•

If OT occurs, the LDO is switched OFF with a 16 µs filter time. The output decreases until UV is detected.

The regulator goes in REC state and can restart only when OT flag is reset. The corresponding SPI bit is

set and FAULT pin is asserted.

4.2.8

VREF

L5965 includes a 1% precise voltage reference output to supply a system ADC. Output voltage can be selected

via OTP cell (4.1 V, 3.3 V, 2.5 V or 1.8 V).

VREF provides the following diagnostic:

•

Over Current limitation in case of over-load or short to ground.

•

Monitor of the output voltage by an independent circuit for UV/OV detection.

VREF Fault management:

•

In case of OV, the power stage is turned off, the fault SPI bit is set and the FAULT pin is asserted. The

power stage is turned on again when the OV is removed.

•

In case of UV, the fault SPI bit is set and the FAULT pin is asserted.

•

In case of OC on VREF for 4 ms, the SPI register fault bit is set and VREF turns off. The FAULT pin is

asserted. VREF turns on again when OC is removed.

L5965

Voltage regulators and features description

DS12567 - Rev 3

page 22/73

L5965 数据表(PDF) 22 Page - STMicroelectronics

L5965 数据表(HTML) 22 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73

数据表下载