DB3264 Rev 3

11/24

L99UDL01

Device description

22

external MOSFET) are disabled and the V3V3IUV bit is set in the SPI diagnostic register

13h.

all of the registers are RESET to their default state and held there.

mode.

2.3

Charge pump

the charge pump has a current limitation. In standby mode or after a global thermal

shutdown has been triggered the charge pump is disabled.

Figure 3. Charge pump low filtering and start-up

voltage crosses the VCPLOW threshold. The CPLOW bit will remain set indicating that the

charge pump was low since the last reading of the register.

At any time the charge pump output voltage drops below VCPLOW and remains there for

low, switching off the external MOSFETs, and CPLOW bit is set.

The outputs are enabled as soon as the charge pump voltage exceeds the VCPLOW

edge according to configuration registers. Outputs that are actuated by the output override

(OUTx_on) bits will automatically turn back on when the charge pump is above CPLOW for

The CPLOW bit will remain set indicating that the charge pump was low since the last read

& clear of the register.

disabled and automatically restarted after VS recovered to normal operating voltage.

The charge pump frequency can be dithered to reduce the impact on radio frequency

emissions. This option is set via bit DITHN in register 03H. By default DITHN=0 and

dithering is enabled.

2.4

Output functionality

There are two groups of three drivers each. The three drivers in each group can be

paralleled or driven independently.