rt8803a Richtek Technology Corporation, rt8803a Datasheet - Page 26

• Manufacturer Part Number: rt8803a
• Description: 2/3-phase Controller High-density Power Supply
• Manufacturer: Richtek Technology Corporation

RT8803A
Error Amplifier Characteristic
For fast response of converter to meet stringent output
current transient response, RT8803A provides large slew
rate capability and high gain-bandwidth performance.
www.richtek.com
26
V
V
Figure 17. EA Falling Transient with 10pF Loading ;
Figure 16. EA Rising Transient with 10pF Loading ;
COMP
COMP
V
V
FB
FB
CH1:(500mV/Div)
CH2:(2V/Div)
Slew Rate = 10V/μs
Slew Rate = 8V/μs
EA
EA
Time (250ns/Div)
Time (250ns/Div)
Falling Slew Rate
Rising Slew Rate
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CH1:(500mV/Div)
CH2:(2V/Div)
Design Procedure Suggestion
a. Output filter pole and zero (Inductor, output capacitor
b. Error amplifier compensation & saw-tooth wave
c. Kelvin sense for V
Current Loop Setting
a. GM amplifier S/H current (current sense component
b. Over-current protection trip point (R
VRM Load Line Setting
a. Droop amplitude (ADJ pin resistor).
b. No load offset (R
c. DAC offset voltage setting (OFS pin & compensation
d. Temperature coefficient compensation(TSEN external
Power Sequence & SS
DVD pin external resistor and SS pin capacitor.
PCB Layout
a.Kelvin sense for current sense GM amplifier input.
b.Refer to layout guide for other items.
Figure 18. Gain-Bandwidth Measurement by signal A
value & ESR).
amplitude (compensation network).
DCR, ISP
network resistor).
resister & thermistor, resistor between ADJ and GND.)
X
and ISN
B
divided by signal B
4.7k
CSN
CORE
X
)
pin external resistor value).
.
V
+
-
4.7k
EA
REF
DS8803A-05 August 2007
IMAX
A
resistor).