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4-6
Troubleshooting
Models 2510 and 2510-AT
Analog circuits
Figure 4-2 shows a block diagram of the analog circuits. These circuits are discussed in
more detail in the following paragraphs.
Source circuits
The Model 2510 source is a digitally controlled, class D power amplifier with the output
stage in an H-bridge configuration. U127 is a 16-bit DAC that controls the pulse-width modu-
lator U110. The H-drive IC, U107, switches the four output FETs, Q107 - Q110. Output filter-
ing is provided by L106, L107, L115, and associated components. Control information for the
DAC and H-drive circuit is fed through serial-to-parallel converter U143.
The source amplitude voltage is controlled by varying the duty cycle of the pulse-width
modulator and, ultimately, the output stage with the digital control information fed to the DAC
and the serial-to-parallel converter. For example, with a duty cycle of 50%, the output is 2.5V.
The hardware current limit circuit consists of R102, U105, U132, and associated compo-
nents. The output stage current that flows through R102 develops a voltage that is amplified by
U105 and compared with a programmed current limit in 10-bit DAC U132. If the current value
exceeds the pre-programmed limit, the H-drive IC is disabled, turning off the output stage.
Class D Amplifier
Figure 4-3 shows a simplified schematic of the class D amplifier output stage. The H_DAC
converts control information from the processor into an analog signal that controls the pulse-
width modulator (PWM) through the H-bridge control. The IP_DAC converts current limit
control information from the processor and forms the BRIDGE OFF signal that turns off the
output stage in an over-current condition.
Sensor
Signal
Conditioning
U124
U149
DAC
U127
H Drive
U107
Class D
Output
Stage
Q107-
Q110
Pulse
Width
Modulator
U110
TEC
I/V
Sensing
U147
U151
Over
Current
Limit
R102
U105
U132
Source
Control
Register
U143
Measure
Control
Register
U134-
U136
Mux
U142
Output
Filter
L106
L107
L115
OUTPUT
Terminals
INPUT
Terminals
Measure Signal
To A/D
Converter
Digital Control
From MPU
Figure 4-2
Block diagram of
analog circuits
2510-902-01 (E - Mar 2010)(Service).book Page 6 Tuesday, March 16, 2010 1:04 PM
Содержание TEC SourceMeter 2510
Страница 3: ...2510 902 01 E Mar 2010 Service book Page 2 Tuesday March 16 2010 1 04 PM...
Страница 14: ...1 PerformanceVerification 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Страница 28: ...2 Calibration 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Страница 54: ...3 RoutineMaintenance 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Страница 58: ...4 Troubleshooting 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Страница 76: ...5 Disassembly 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Страница 82: ...6 ReplaceableParts 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Страница 92: ...A Specifications 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 2 33 PM...
Страница 96: ...B CalibrationReference 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Страница 110: ...C CalibrationProgram 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Страница 119: ...2510 902 01 E Mar 2010 Service book Page 4 Tuesday March 16 2010 1 04 PM...