LM27761
www.ti.com.cn
ZHCSEO7C –OCTOBER 2015–REVISED JANUARY 2017
In typical high-current applications, 0.47-µF or 1-µF 10-V low-ESR ceramic capacitors are recommended for the
flying capacitors. Polarized capacitors (tantalum, aluminum, electrolytic, etc.) must not be used for the flying
capacitor, as they could become reverse-biased during LM27761 operation.
8.2.2.6.4 LDO Output Capacitor
The LDO output capacitor (C4) value and the ESR affect stability, output ripple, output noise, PSRR and
transient response. The LM27761 only requires the use of a 2.2-µF ceramic output capacitor for stable operation.
For typical applications, a 2.2-µF ceramic output capacitor located close to the output is sufficient.
8.2.3 Application Curves
100
10
1
200
100
25°C
85°C
-40°C
25°C
85°C
-40°C
10
1
0.001
0.001
0.01
IOUT (A)
0.1
0.25
0.01
IOUT (A)
0.1
0.25
D003
D004
VIN = 3 V
VOUT = –1.8 V
VIN = 5.5 V
VOUT = –5 V
图 18. Charge-Pump Output Impedance vs
图 19. Charge-Pump Output Impedance vs
Output Current
Output Current
VIN = 3 V
VOUT = –1.8 V
VIN = 4V to 4.5 V
VOUT = –1.8 V
IOUT = 100 mA
图 21. Load Step
图 20. Line Step
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