HM9270C Datasheet, PDF (1/10 Pages) ELAN Microelectronics Corp – DTMF RECEIVER

HM 9270C/D
DTMF RECEIVER
General Description
The HM 9270C/D is a complete DTMF receiver integrating both the bandsplit filter and digital decoder
functions. The filter section uses switched capacitor techniques for high- and low-group filters and dial-tone
rejection. Digital counting techniques are employed in the decoder to detect and decode all 16 DTMF tone-
pairs into a 4-bit code. External component count is minimized by on-chip provision of a differential input
amplifier, clock-oscillator and latched 3-state bus interface.
Features
• Complete receiver in an 18-pin package.
• Excellent performance.
• CMOS, single 5 volt operation.
• Minimum board area.
• Central office quality.
• Low power consumption.
• Power-Down mode (HM9270D only).
• Inhibit-mode (HM9270D only).
Pin Configurations
HM9270C
IN+ 1
IN 2
GS 3
V_REF
4
IC* 5
IC* 6
OSC1 7
OSC2 8
V_SS
9
18 ^VDD
17 St/GT
16 _ESt
15 StD
14 Q4
13 Q3
12 _Q2
11 Q1
10 _TOE
HM9270D
IN+ 1
IN 2
GS 3
V_REF
4
INH 5
PWDN 6
OSC1 7
OSC2 8
V_SS
9
18 ^VDD
17 St/GT
16 _ESt
15 StD
14 Q4
13 Q3
12 _Q2
11 Q1
10 _TOE
* Connect to V
SS
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