Standard Bias Table; Table 4-4. Standard Operating Bias - Motorola ASTRO Digital Spectra Plus Service Manual

Troubleshooting Procedures: ASTRO Spectra Procedures
4.1.5

Standard Bias Table

Table 4-4, below, outlines some standard supply voltages and system clocks which should be
present under normal operation. These should be checked as a first step to any troubleshooting
procedure.
Signal Name
UNSW_B+
SW_B+
+5V
+5VA
RESET
POR*
DSP_RST*
ADSIC_RST*
DCLK
ODC
ECLK
IRQB*
+5V
RX_5V
a. This number may vary due to the operating mode of the radio
b. This 8 kHz clock will be present only after the MCU has
c. Receive mode only.
6881076C25-D

Table 4-4. Standard Operating Bias

Nominal Value
13.8 Vdc
13.8 Vdc
5.0 Vdc
5.0 Vdc
5.0 Vdc
5.0 Vdc
5.0 Vdc
5.0 Vdc
33.0000 MHz
2.4 MHz
1.8432 MHz
b
8 kHz
5.0 Vdc
c
5.0 Vdc
when it is measured. The ADSIC contains a divider which may
divide the clock by a modulus of 2. Therefore, the actual
frequency measured may be clock/2
frequency will be 16.5000 MHz nominal.
successfully programmed the ADSIC after power-up. This is a
good indication that the ADSIC is at least marginally
operational.
Tolerance
11.0-16.6 Vdc
11.0-16.6 Vdc
±10%
±10%
+0.7, - 1.0 Vdc
+0.7, - 1.0 Vdc
+0.7, -1.0 Vdc
+0.7, -1.0 Vdc
a
±500 ppM
±30 ppM
±500 ppM
±500 ppM
±10%
±10%
n
. The most common
Source
J501
J501
J501
J501
J501
J501
U204
U204
U406
ABACUS
U204
U406
U202
U106
October 28, 2002
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