The Sony CMD-CD5 exposes a bottom I/O connector on the base of the phone for its charger and accessories (headset, hands-free kit, desktop charger, PCMCIA and EasyCom data adapters). It carries the charging contacts, a serial data pair, a single-ended audio in/out pair, and accessory identification and detection lines. The documented contacts are listed below.
| Pin | Signal | Description |
|---|---|---|
| 1 | Charge | Positive charging contact |
| 2 | Charge | Positive charging contact |
| 3 | ACC Power | Accessory power supply |
| 6 | ACC Detect | Accessory insertion/removal detect (interrupt) |
| 9 | TX (out) | Serial transmit data (from the phone) |
| 10 | RX (in) | Serial receive data (into the phone) |
| 11 | ACC ID | Accessory present / analogue accessory ID |
| 12 | AGND | Audio ground (reference for Audio In and Audio Out) |
| 13 | Audio Out | Single-ended audio output (0.8 Vpp into 1 kΩ) |
| 14 | Audio In | Single-ended audio input (max sensitivity 365 mVrms) |
| 18 | GND | Ground — digital interface and charger return current |
Signals
- Charge — positive contact for the charging function (pins 1 and 2); an accessory with an active charge wakes the phone, and charger insertion/removal is detected by polling.
- ACC Power — supply provided to the accessory.
- ACC Detect — signals insertion and removal of a non-charging accessory via an interrupt (only while the phone is powered up).
- TX / RX — the serial data pair (TX out of the phone, RX into the phone) used by the data adapters.
- ACC ID — signals the presence of an accessory and provides an analogue ID identifying it; the ID is read before accessory power is applied.
- Audio In / Audio Out — single-ended audio interface to a headset or hands-free kit, referenced to AGND.
- AGND — analogue ground reference for the audio signals.
- GND — ground return for the digital interface and for charger current.
References
- Sony CMD-CD5 Service Manual — Accessory Interface connector (§2.6) — Sony Corporation.