


Nokia 31xx/81xx
 (at the cellular phone)
NOKIA SPECIAL at the cellular phone.
  
    | Pin | 
    Name | 
    Description | 
  
  
    | 1 | 
    GND | 
    Charger/System Ground | 
  
  
    | 2 | 
    V_OUT | 
    Accessory Output Supply. (3.4V...10V - 50mA) | 
  
  
    | 3 | 
    XMIC | 
    External Microphone Input and Accessory Identification | 
  
  
    | 4 | 
    EXT_RF | 
    External RF Control Input | 
  
  
    | 5 | 
    TX | 
    FBUS Transmit | 
  
  
    | 6 | 
    MBUS | 
    Serial Control Bus | 
  
  
    | 7 | 
    BENA | 
    Not Connected | 
  
  
    | 8 | 
    SGND | 
    Signal Ground | 
  
  
    | 9 | 
    XEAR | 
    External Speaker and Mute Control | 
  
  
    | 10 | 
    Hook | 
    Hook Signal | 
  
  
    | 11 | 
    RX | 
    FBUS Receive | 
  
  
    | 12 | 
    V_IN | 
    Charging Supply Voltage (Max 16V) | 
  
XMIC: External Microphone Input and Accessory Identification
  
    | U low | 
    U high | 
    Description | 
  
  
    | 1.15 V | 
    1.4 V | 
    Compact Handsfree Unit Connected | 
  
  
    | 1.7 V | 
    2.05 | 
    Headset Adapter Connected | 
  
  
    | 2.22 V | 
    2.56 V | 
    Infra Red Link Conneceted | 
  
EXT_RF: External RF Control Input
  
    | U low | 
    U high | 
    Description | 
  
  
    | 0.0 V | 
    0.5 V | 
    External RF in use | 
  
  
    | 2.4 V | 
    3.2 V | 
    Internal Antenna in use | 
  
MBUS: Serial Control Bus
  
    | U low | 
    U high | 
    Description | 
  
  
    | 0.0 V | 
    0.5 V | 
    Logic Low Level | 
  
  
    | 2.4 V | 
    3.2 V | 
    Logic High Level | 
  
XEAR: External Speaker and Mute Control
  
    | U low | 
    U high | 
    Description | 
  
  
    | 0.0 V | 
    0.5 V | 
    Mute ON (HF Speaker Mute) | 
  
  
    | 1.0 V | 
    1.7 V | 
    Mute OFF (HF Speaker Active) | 
  
Hook: Hook Signal
  
    | U low | 
    U high | 
    Description | 
  
  
    | 0.0 V | 
    0.5 V | 
    Hook Off (Handset in Use) | 
  
  
    | 2.4 V | 
    3.2 V | 
    Hook On (Handset in Use) | 
  
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  May be copied and redistributed, partially or in whole, as appropriate.
  Document last modified: 2002-01-10