LP3910 Datasheet, PDF (37/72 Pages) Texas Instruments – Power Management IC for Hard-Drive-Based Portable Media Players

www.ti.com
VBATT
ADC1
ADC2
LP3910
SNVS481M – NOVEMBER 2006 – REVISED DECEMBER 2015
ISET
MUX_CONTROL
2
Current range 0 / 1
Icharge
Scaler
Vbatt
Scaler
Voltage range 0 / 1
ADC
MUX
To ADC
core
Figure 59. ADC Analog Front-End Block Diagram
The source selection and the access to the conversion results are established through the I²C linked control
registers: ADCC and ADCD.
The ADC is by default disabled to minimize current consumption and must be enabled by setting D2 in the ADCC
register. Writing a logic 1 to bit D3 in the ADC initiates a conversion. It is advised to select the correct ADC
source before a conversion is started. The ADC sets bit D4 in the ADCC register upon the completion of a
conversion, which is typically 4 ms after the start of the conversion. At the same time an interrupt request is
generated. (See IRQ Register (0d)H Interrupt Request Register).
To save power, disable the ADC by setting bit 2 of D2 to 0. To make repetitive starts, set bit D3 to 0 then to 1 for
register 0Ah to initiate start of conversion. The interrupt driven protocol between LP3910 and the system
processor is the most efficient way to acquire data from successive measurements as shown in Figure 60:
Copyright © 2006–2015, Texas Instruments Incorporated
Product Folder Links: LP3910
Submit Documentation Feedback
37