View pcd3310 fam 3 datasheet:

INTEGRATED CIRCUITS DATA SHEET PCD3310; PCD3310A Pulse and DTMF diallers with redial 1996 Nov 21 Product specification Supersedes data of 1996 May 06 File under Integrated Circuits, IC03 Philips Semiconductors Product specification Pulse and DTMF diallers with redial PCD3310; PCD3310A CONTENTS 1 FEATURES 2 GENERAL DESCRIPTION 3 QUICK REFERENCE DATA 4 ORDERING INFORMATION 5 BLOCK DIAGRAM 6 PINNING 7 FUNCTIONAL DESCRIPTION 7.1 Power supply (VDD and VSS) 7.2 Clock oscillator (OSCI and OSCO) 7.3 Chip enable (CE) 7.4 Mode selection (PD/DTMF) 7.4.1 Pulse mode 7.4.2 DTMF mode 7.4.3 Mixed mode 7.5 Keyboard inputs/outputs 7.6 Flash duration control (FLD) 7.7 TONE output (DTMF mode) 7.8 Dial pulse and Flash output (DP/FLO) 7.9 Mute output (M1) 7.10 Mute output (M1) 7.