AAT1187A Advanced Analog Technology, Inc., AAT1187A Datasheet - Page 23

• Manufacturer Part Number: AAT1187A
• Description: Boost Converter For Wled Driver
• Manufacturer: Advanced Analog Technology, Inc.

Figure 6. Bode Plot of Loop Gain Using Matlab
However, it is found that the measured gain increased
because of the extra small signal path provided by the
10
formula is presented in this thesis to improve the gain
observed in bode plot. Theoretically calculated result is
confirmed by measurement data.
Loss(dB) = 20dB+20log10(10/r)
R = VADD/I
Loss(dB) = 7dB
resistor in the spectrum analyzer. A modified
Simulation
O
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Figure 7. Bode Diagram of Loop Gain Using
(Red line: gain of measurement, Blue line: phase of
measurement, Black line: correct gain).
Setting the V
The positive charge pump driver provides a regulated
output voltage set by a resistor divider from the V
GND with a center tap connected to the FBP.
V
voltage feedback voltage is typically 1.24V.
Set R
calculate R
R
FBP
7
is the positive LDO driver feedback regulation and
R
8
8



(Figure8) between 5.1k
–
Figure 8. The Positive LDO Driver
Frequency Response Analyzer
Measurement
V
V
7
FBP
GH
with the following equation.
GH
1



Output Voltage
AAT1187A
and 51k , and
September 2009
GH
to