Hytera MD78X, Service Manual

Page: 151 / 519

Interface Definition
UHF2 (450
–
520 MHz)
38
Pin
No.
Name Type
Signal Electrical
Performance
Description
7 Mic input Analog input
Modulation sensitivity
Vrms=80mV±10%@1kHz
60%system max. deviation
Mic input for palm microphone
8 USB_D+
USB data
cable+
USB data
When this pin is used for USB
function, USB function of DB26
will be disabled.
9 HOOK Digital input 3.3V CMOS
High level by default; valid at low
level.
HOOK and MONITOR functions:
Press this key, the level
changes from high to low. When
palm microphone is detected or
press the key of the palm
microphone, this pin is used for
HOOK function; when desktop
microphone is detected, this pin
is used for MONITOR function.
10
Accessory
identification
interface 2
Digital input 3.3V CMOS
Pin 1 and Pin 10 (accessory
identifier interface 1) compose
an accessory identification
matrix. Please refer to the
“
10-pin Accessory Identification
Matrix Table ” below for detailed
function definitions.
10-pin Accessory Identification Matrix Table (composed of Pin 1 and Pin 10):
Pin 1 Pin 10 Radio Status
Low level Low level Reserved
Low level High level
The mobile radio is in USB master mode or connected to a USB
smart accessory (such as palm microphone with keypad).
High level Low level
The mobile radio is connected to an external speaker (including