L99MC6GJ datasheet(12/55 Pages) STMICROELECTRONICS

12 / 55 page

Description

L99MC6GJ

12/55

DocID026835 Rev 3

Description

2.1

Dual power supply: VS and VCC

The supply voltage VCC (3.3 V/5 V) supplies the whole device. In case of power-on (VCC

increases from undervoltage to VPOR OFF = 2.7 V, typical) the circuit is initialized by an

internally generated power-on reset (POR). If the voltage VCC decreases under the

minimum threshold (VPOR ON = 2.4 V, typical), the outputs are switched-off (high-

impedance) and the status registers are cleared (see Figure 4).

Figure 4. Power-on reset

2.1.1

Channels

The channels 1 to 3 are self configuring high-side or low-side n-channel mosfets. This

flexibility allows the user to connect loads in high-side or low-side configuration in any

combination.

In order to provide low Rdson values for high-side configured switches (channels 1 to 3), a

charge pump (CP) to drive the internal gate voltage(s) is implemented. If the charge pump is

activated (ENCP1 = 1, DISCP2 = 0, see Section 9.3: Control and status registers), the

internal charge-pump uses VS from the drain of channel 1, as its power source. Otherwise

VCC is used to drive all channels.

The channels 4 to 6 are n-channel low-side drivers. The source of the respective mosfet are

internally connected to the device GND.

Caution:

For any high-side configuration, channel 1 must be used as a high-side switch.

If channel 1 is configured as low-side, the charge pump has to be deactivated to avoid

charge pump current from the drain.

Caution:

The charge pump may not be deactivated (see Section 9.3: Control and status registers) if

one of the channels is in high-side configuration, while a short-circuit from the source to the

battery is present. If these conditions occur, the voltage of the shorted source is applied to

the VCC pin.

L99MC6GJ датащи(PDF) 12 Page - STMicroelectronics