LTC3252 Datasheet, PDF (4/12 Pages) Linear Technology – Dual, Low Noise, Inductorless Step-Down DC/DC Converter

LTC3252
TYPICAL PERFOR A CE CHARACTERISTICS
Oscillator Max/Min Frequency vs
Supply Voltage
2.0
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
2.7
–40°C MAX ^{25°C MAX}
85°C MAX
25°C MIN
–40°C MIN
85°C MIN
3.2 3.7 4.2 4.7
V_IN (V)
5.2
3252 G07
1.2V Output Voltage vs Supply
Voltage
1.30
1.28 ^{TA = 25°C}
1.26
1.24
1.22
I_OUT = 0mA
1.20
I_OUT = 50mA
1.18
I_OUT = 250mA
1.16
1.14
1.12
1.10
2.7 3.2 3.7 4.2 4.7 5.2
V_IN (V)
3252 G08
1.2V Efficiency vs Load Current
100
T_A = 25°C
80
60
40
20
0
0.1
V_IN = 2.8V
V_IN = 3.1V
V_IN = 3.5V
V_IN = 4.5V
1
10
100
I_OUT (mA)
1000
3252 G09
Output Current Transient
Response
Line Transient Response
250mA
I_OUT
20mA
V_OUT
20mV/DIV
AC
4.5V
V_IN
3.5V
V_OUT
10mV/DIV
AC
V_IN = 3.6V
V_OUT = 1.5V
3252 G11
V_OUT = 1.5V
I_OUT = 150mA
3252 G12
PI FU CTIO S
FB1 (Pin 1): Feedback Input Pin 1. An output divider
should be connected from OUT1 to FB1 to program the
output voltage.
EN1 (Pin 2): Input Enable Pin 1. When EN1 is high, OUT1
is enabled. When EN1 is low OUT1 is shut down.
V_IN (Pin 3): Input Supply Voltage. Operating V_IN may be
between 2.7V and 5.5V. Bypass V_IN with a ≥ 4.7µF (1µF
min) low ESR ceramic capacitor to GND (C_IN).
C1⁺ (Pin 4): Flying Capacitor 1 Positive Terminal (C1).
OUT1 (Pin 5): Regulated Output Voltage 1. OUT1 is
disconnected from V_IN when in shutdown. Bypass OUT1
with a low ESR ceramic capacitor to GND (C_O1). See
Output Capacitor Selection section for size requirements.
C1^– (Pin 6): Flying Capacitor 1 Negative Terminal (C1).
GND (Pin 7): Ground. Connect to a ground plane for best
performance.
3252f
4