TSC2102 datasheet(21/54 Pages) TI

21 / 54 page

TSC2102

SLAS379A− APRIL 2003 − REVISED JUNE 2004

www.ti.com

ADC

VBAT

10 k

Ω

2 k

Ω

LDO or DC-DC

Converter

2.7 V to 3.6 V

VDD

−

Battery

0.5 to 6 V

Figure 17. Battery Measurement Functional Block Diagram

Battery measurement can only be done in host controlled mode.

See the section Conversion Time Calculation for the TSC2102 and subsection Non Touch Measurement Operation in this

data sheet for timing diagrams and conversion time calculations.

Auxiliary Measurement

The auxiliary voltage input (AUX) can be measured in much the same way as the battery inputs. Applications might include

external temperature sensing, ambient light monitoring for controlling the back-light, or sensing the current drawn from the

battery. The auxiliary input can also be monitored continuously in scan mode.

Auxiliary measurement can only be done in host controlled mode.

See the section Conversion Time Calculation for the TSC2102 and subsection Non Touch Measurement Operation in this

data sheet for timing diagrams and conversion time calculations.

Port Scan

If making measurements of BAT1, BAT2, and AUX is desired on a periodic basis, the port scan mode can be used. This

mode causes the TSC2102 to sample and convert both battery inputs and the auxiliary input. At the end of this cycle, the

battery and auxiliary result registers contain the updated values. Thus, with one write to the TSC2102, the host can cause

three different measurements to be made.

Port scan can only be done in host−controlled mode.

See the section Conversion Time Calculation for the TSC2102 and subsection Port Scan Operation in this data sheet for

timing diagrams and conversion time calculations.

Hardware Reset

The device requires hardware reset (active low) after power up. A hardware reset pulse initializes all the internal registers

and counters.

Hardware Power Down

The device powers down all the internal circuitry to save power. All the register contents are maintained. Some counters

maintain their value. The hardware power-down circuit also disables the pen-touch detect circuit.

TSC2102 Folha de dados(PDF) 21 Page - Texas Instruments