User's Manual

68P80801E35-B 5/1/2002 9
EBTS System Manual - Vol 2 800/900/1500 MHz Base Radios
DC Power Supply
+5.1 V INVERTER CIRCUITRY
FET
DRIVER
POWER FET
SWITCH
FILTER
CIRCUITRY
VCC
VCC
+ 5V OVERCURRENT
DETECT
REF
REF
SURGE CURRENT
DELAY
REF
OVERVOLTAGE
DETECT
FET
CROWBAR
CIRCUIT
+ 28V BULK
PULSE
WIDTH
MODULATOR
A
24
25
30
31
+5.1 V DC
TO
STATION
MODULES
VIA
BACKPLANE
P/O
BACKPLANE
CONNECTOR
+5.1 V
÷ 2
CLOCK GENERATOR CIRCUITRY
STARTUP INVERTER CIRCUITRY
BULK DETECT
TO
DIAGNOSTICS
CIRCUITRY
PULSE
WIDTH
MODULATOR
VCC
VCC
STARTUP ISOLATION
TRANSFORMER
+14.2 V INVERTER CIRCUITRY
FET
DRIVER
POWER FET
SWITCH
FILTER
CIRCUITRY
VCC
VCC
+ 14.2V OVERCURRENT
DETECT
REF
REF
SURGE CURRENT
DELAY
REF
OVERVOLTAGE
DETECT
FET
CROWBAR
CIRCUIT
A
16
17
22
23
+14.2V DC
TO
STATION
MODULES
VIA
BACKPLANE
P/O
BACKPLANE
CONNECTOR
+14.2V
+14.2V
PULSE
WIDTH
MODULATOR
PULSE
WIDTH
MODULATOR
FRONT PANEL
ON / OFF
SWITCH
EXTERNAL
DC INPUT
41-60 VDC
FILTER
CIRCUITRY
INPUT FILTER BOARD
3
4
14
15
+28.6 VDC
TO
STATION
MODULES
VIA
BACKPLANE
P/O
BACKPLANE
CONNECTOR
MAIN INVERTER CIRCUITRY
REF
REF
CURRENT
DETECT
A
+28.6 V OVERVOLTAGE
DETECT
+28 V BULK TO
DIAGNOSTICS
CIRCUITRY
OVERCURRENT
DETECT
+28.6 VDC
CLOCK
GENERATOR
CIRCUITRY
267 KHZ
TRANSISTOR
SWITCH
B
MAIN ISOLATION
TRANSFORMER
TRANSISTOR
DRIVERS
SOFTSTART
CIRCUITRY
SHUTDOWN
A
+12V STARTUP BIAS
+12V STARTUP BIAS
VCC
VCC
MOD FAIL
133 KHZ
267 KHZ
133 KHZ
133 KHZ
133 KHZ
133 KHZ
133 KHZ
267 KHZ
133 KHZ
267 KHZ
133 KHZ
POWER FET
SWITCHES
FILTERING
CIRCUITRY
+28 V BULK
EBTS323
011497JNM
Figure 3
DC Power Supply Functional Block Diagram (Sheet 1 of 2)