OP7100
Hardware 25
Power Management
The OP7100 was designed to operate from a 12 V to 30 V DC source, and
consumes about 4.5 W with the backlight on, 1.5 W with the backlight off.
To allow for a surge current when the OP7100 is first turned on, the power
supply used must be able to handle at least four times this power (for
example, 800 mA at 24 V).
The OP7100 power supply is converted internally to supply three voltages.
1. A switching regulator outputs VCC (+ 5 V).
2. A linear regulator outputs VEE (approximately –20 V).
3. A high-voltage section supplies 300 V rms to drive the cold-cathode
fluorescent backlight. The backlight can be turned on or off under
software control whereby a high on the gate of Q3 enables Q1 and Q2 to
oscillate, and a low turns off Q3, stopping the oscillation of Q1 and Q2.
Figure 3-2 shows these internal power supplies in a block diagram
Figure 3-2. Block Diagram of OP7100 Internal Power Regulators
The DC input source can also be brought out on pin 9 of header J10, the
DE-9 connector, by installing a 0
Ω
resistor at R32. This option allows
power to be supplied to a serial device connected to the OP7100 as long as
the serial device’s RS-232 port can handle the DC input on pin 9.
Be sure to use a power supply with sufficient capacity (for
example, 1.1 A at 24 V) to handle surges when the OP7100
and any devices connected to it are first turned on.
VCC
J10:9
1230 V DC
J11:5
1230 V DC
U28
2575
Sw Reg
U27
2951
Lin Power
U25
7662
Sw Reg
U23
7662
Sw Reg
VEE
VCC
2575
Sw Reg
Backlight
Power
from EPLD
300 V rms, 32.7 kHz,
to CCFL backlight
Q3
Summary of Contents for OP7100
Page 1: ...OP7100 Serial Graphic Display User s Manual 019 0065 070831 O ...
Page 10: ...OP7100 x About This Manual ...
Page 16: ...OP7100 16 Overview ...
Page 74: ...OP7100 74 Software ...
Page 82: ...OP7100 82 Graphics Programming ...
Page 88: ...OP7100 88 Installation ...
Page 98: ...OP7100 98 Specifications ...
Page 108: ...OP7100 108 Memory I O Map and Interrupt Vectors ...
Page 112: ...112 Serial Interface Board 2 OP7100 ...
Page 113: ...OP7100 Backup Battery 113 APPENDIX E BACKUP BATTERY ...
Page 116: ...OP7100 116 Backup Battery ...
Page 124: ...OP7100 124 Index ...
Page 126: ...XX0000 Schematics ...