M62301SP datasheet(4/12 Pages) RENESAS

4 / 12 page

M62301SP/FP

REJ03D0861-0300 Rev.3.00 Mar 25, 2008

Page 4 of 11

Operating Description

(1) Decoder

Based on digital inputs to C0, C1, C2, the analog switch is set to on, and the input of "0" scale (GND input), input of

reference scale (reference voltage input), input to A1-A4, or discharge from integration capacitor (CI) is performed.

None of these operations is performed when the "mode 8" input is given:

Mode

Discharge

GND

VREF

—

(2) A/D conversion

Decoder selection mode

VIN + 0.49 V

VREF + 0.49 V

0.49 V

0.36 V

V (8)

4 to 7

TIN

TREF

TGND

Multiplexer first selects VGND, obtaining minimum pulse TGND. It then selects VREF, obtaining reference pulse TREF.

Input is selected next, obtaining input pulse TIN. VIN is obtained by deducting TGND, as the offset, from TREF and TIN.

VIN = VREF •

TIN − TG

TREF − TG

By measuring voltage at the maximum input for approximately 500

µs under the counter clock of 8 MHz, resolution

of approximately 12 bits can be obtained;

500

µs

125 ns

≈ 212

Note: To ensure discharge from capacitor CI, the decoder input as in the above diagram should stay in mode 1 at least

for the period calculated above:

It is not necessary to measure TGND, and TREF for each channel.

Tdi = (CI ×

)

VIAmax + 0.49

1 mA

M62301SP Arkusz danych(PDF) 4 Page - Renesas Technology Corp

M62301SP Arkusz danych(HTML) 4 Page - Renesas Technology Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12

Arkusz danych Pobierz

Link URL