LM3200 Datasheet, PDF (5/24 Pages) National Semiconductor (TI) – Miniature, Adjustable, Step-Down DC-DC Converter with Bypass Mode for RF Power Amplifiers

LM3200
www.ti.com
SNVS319C – NOVEMBER 2004 – REVISED APRIL 2013
SYSTEM CHARACTERISTICS
The following spec table entries are specified by design if the component values in the typical application circuit are used.
These parameters are not specified by production testing.
Symbol
Parameter
Conditions
Min
Typ
Max
Units
T_RESPONSE Time for V_OUT to Rise
from 0.8V to 3.4V in
PWM Mode
V_IN = 4.2V, C_OUT = 4.7 µF,
R_LOAD = 15Ω
L = 2.2 uH
25
µs
C_CON
V_CON Input Capacitance V_CON = 1V,
Test frequency = 100 kHz
15
pF
T_{ON_BYP}
Bypass FET Turn On
Time In Bypass Mode
T_BYP
Auto Bypass Detect
Delay Time
V_IN = 3.6V, V_CON = 0.267V,
C_OUT = 4.7 µF, R_LOAD = 15Ω
BYP = Low to High
(1)
30
µs
10
15
20
µs
(1) V_IN is compared to the programmed output voltage (V_OUT). When V_IN–V_OUT falls below V_BYPASS− for longer than T_BYP the Bypass FET
turns on and the switching FETs turn off. This is called the Bypass mode. Bypass mode is exited when V_IN–V_OUT exceeds V_BYPASS+ for
longer than T_BYP, and PWM mode returns. The hysterisis for the bypass detection threshold V_BYPASS+ – V_BYPASS− will always be
positive and will be approximately 200 mV(typ.).
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