This page documents the proprietary multi-pin bottom connector found on Nokia 31xx and 81xx series handsets, as used by third-party data, charging, and accessory cables. The connector layout is specific to these model families and differs from connectors used on other Nokia ranges. Only the pins relevant to cable and accessory use are listed below.
| Pin | Signal | Description |
|---|---|---|
| 1 | GND | Charger/System Ground |
| 2 | V_OUT | Accessory Output Supply. (3.4V…10V - 50mA) |
| 3 | XMIC | External Microphone Input and Accessory Identification 1,7…2,05 V Headset Adapter Connected 1,15…1,4 V Compact Handsfree Unit Connected *2.22…2.56 V Infra Red Link Conneceted |
| 4 | EXT_RF | External RF Control Input 0…0.5V External RF in use 2.4…3.2V Internal Antenna in use |
| 5 | TX | FBUS Transmit |
| 6 | MBUS | Serial Control Bus Logic Low Level: 0….0.5V Logic High Level:2.4V….3.2V |
| 7 | BENA | Not Connected |
| 8 | SGND | Signal Ground |
| 9 | XEAR | External Speaker and Mute Control Mute ON (HF SPEAKER MUTE ):0…0,5 V d.c. Mute OFF (HF SPEAKER ACTIVE ): 1,0…1,7 V d.c. |
| 10 | Hook | Hook Signal Hook Off (Handset in Use): 0….0.5V Hook On (Handset in Use): 2.4V….3.2V |
| 11 | RX | FBUS Receive |
| 12 | V_IN | Charging Supply Voltage (Max 16V) |
Notes
Pin numbers refer to the connector on the handset; pins not listed are unused by the cable.
References
- Nokia 3110/3810 Service Manual (NHE-8/NHE-9) — System Connector — Nokia Corporation.