UM9151 Pulse Dialer 5V IC DIP-18
The UM9151 IC DIP-18 is an integrated circuit that provides telephone pulse dialing functionality for telecommunication equipment.
It accepts keypad inputs from a standard 4×3 matrix keypad and converts them into corresponding pulse sequences to interface with legacy telephone systems that use pulse dialing.
The IC is housed in a through-hole 18-pin DIP package, making it easy to prototype and integrate into PCB designs.
Features:
- 4 x 3 matrix single contact keyboard.
- Supply voltage range 2.5V to 5V.
- Inexpensive RC oscillator.
- Low power standby mode for redial.
- 22 digit capacity far redial.
- 18 lead dual-in-line package.
- Redial with either • or # key.
- Dialer reset for line power break → 200 msec.
- Pin selectable inter-digital pause (IDP).
- Pin selectable make/break (M/B).
- High speed test capability.
- Direct telephone line operation.
Specifications:
| Parameter | Value / Notes |
|---|---|
| Part number: | UM9151 |
| Function: | Telephone pulse dialer / keypad interface |
| Technology: | CMOS |
| Package: | DIP-18 (through-hole) |
| supply voltage (Vᴅᴅ): | 5V (CMOS logic supply) |
| Supply voltage range: | 2.5V to 5V |
| Quiescent current: | Low (CMOS) |
| Inputs: | 4×3 keypad matrix compatible, CMOS logic level |
| Outputs: | Pulse dialing output / control outputs |
| Operating temperature: | -20°C to 60°C |
| Mounting: | Through-hole |
| External components: | Bypass capacitors, keypad matrix, pull-ups or drivers as required by application |
Pinout:
| Pin | Configuration | Description |
|---|---|---|
| 1 | TEST | Dialing rate = 10pps when connected to Vᴅᴅ (normal) Dialing rate = 600pps when connected to Vꜱꜱ (high speed test) |
| 18, 2, 3, 4 | R1, R2, R3, R4 | Keyboard inputs |
| 5 | Vᴅᴅ | Positive power supply |
| 6, 7, 8 | CKI, CK, CR | These pins are connected to an RC oscillator. (clock frequency control) |
| 9 | DP | Dialing pulse output. The output stage is an N-channel open drain device |
| 10 | M/B | M/B = 33/66% if connected to Vᴅᴅ M/B = 40/60% if connected to Vꜱꜱ |
| 11 | IDP | Iᴅᴘ = 500ms if connected to Vᴅ Iᴅᴘ = 800ms if connected to Vꜱꜱ |
| 12 | HK | On-hook/Off-hook input |
| 13 | MUTE | MUTE output to mute telephone speech circuit |
| 14 | Vꜱꜱ | Negative power supply |
| 15, 16, 17 | C1, C2, C3 | Keyboard outputs |
Applications:
- Telephone pulse-dialer modules and keypad interfaces.
- PABX dialer and legacy telephone equipment.
- Embedded telephony controllers and access control systems.
- DIY telephone and retro telecom projects.
- Any application that requires converting keypad entries to pulse dialing sequences.
Packages:
- 1x UM9151 Pulse Dialer 5V IC DIP-18.
