Datasheet

LTC3577/LTC3577-1
8
3577fa
ELECTRICAL CHARACTERISTICS
LDO Regulators. The l denotes the specifi cations which apply over the
full operating temperature range, otherwise specifi cations are at T
A
= 25°C. V
INLDO1
= V
INLDO2
= V
OUT
= V
BAT
= 3.8V, LDO1 and LDO2
enabled unless otherwise noted.
LED Boost Switching Regulator. The l denotes the specifi cations which apply over the full operating temperature range, otherwise
specifi cations are at T
A
= 25°C. V
IN3
= V
OUT
= 3.8V, R
OV
= 10M, R
LED_FS
= 20k, boost regulator disabled unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
IN3
, V
OUT
Operating Supply Range (Note 9)
l
2.7 5.5 V
I
VOUT_LED
Operating Quiescent Current
Shutdown Quiescent Current
(Notes 10, 14) 560
0.01
µA
µA
V
LED_OV
LED_OV Overvoltage Threshold LED_OV Rising
LED_OV Falling 0.6
1.0
0.85
1.25 V
V
I
LIM
Peak NMOS Switch Current 800 1000 1200 mA
I
LED_FS
I
LED
Pin Full-Scale Operating Current 18 20 22 mA
I
LED_DIM
I
LED
Pin Full-Scale Dimming Range 64 Steps 60 dB
R
NSWON
R
DS(ON)
of NMOS Switch 240 mΩ
I
NSWOFF
NMOS Switch-Off Leakage Current V
SW
= 5.5V 0.01 1 µA
f
OSC
Oscillator Frequency 0.95 1.125 1.3 MHz
V
LED_FS
LED_FS Pin Voltage
l
780 800 820 mV
I
LED_OV
LED_OV Pin Current R
LED_FS
= 20k
l
3.8 4 4.2 µA
D
BOOST
Maximum Duty Cycle I
LED
= 0 97 %
V
BOOSTFB
Boost Mode I
LED
Feedback Voltage
l
775 800 825 mV
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
LDO1_SC
Short-Circuit Output Current 270 mA
V
DROP1
Dropout Voltage (Note 12) I
LDO1
= 150mA, V
INLDO1
= 3.6V
I
LDO1
= 150mA, V
INLDO1
= 2.5V
I
LDO1
= 75mA, V
INLDO1
= 1.8V
160
200
170
260
320
280
mV
mV
mV
R
LDO1_PD
Output Pull-Down Resistance in Shutdown LDO1 Disabled 10 k
LDO Regulator 2 (LDO2 – Enabled via I
2
C)
V
INLDO2
Input Voltage Range V
INLDO2
≤ V
OUT
+ 0.3V
l
1.65 5.5 V
V
OUT_UVLO
V
OUT
Falling
V
OUT
Rising
LDO2 is Disabled Below V
OUT
UVLO 2.5 2.7
2.8 2.9
V
V
I
QLDO2_VO
I
QLDO2_VI
LDO2 V
OUT
Quiescent Current
LDO2 V
INLDO2
Quiescent Current
LDO2 Enabled, PON State, I
LDO2
= 0mA
LDO2 Enabled, PON State, I
LDO2
= 0mA
18
0.1
30
2
µA
µA
I
VINLDO2
Shutdown Current LDO2 Disabled, PON or POFF State 0.01 1 µA
V
LDO2_FB
LDO2_FB Regulated Output Voltage I
LDO2
= 1mA
l
0.78 0.8 0.82 V
LDO2_FB Line Regulation (Note 11) I
LDO2
= 1mA, V
IN
= 1.65V to 5.5V 0.4 mV/V
LDO2_FB Load Regulation (Note 11) I
LDO2
= 1mA to 150mA 5 µV/mA
I
LDO2_FB
LDO2_FB Input Current LDO2_FB = 0.8V –50 50 nA
I
LDO2_OC
Available Output Current
l
150 mA
I
LDO2_SC
Short-Circuit Output Current 270 mA
V
DROP2
Dropout Voltage (Note 12) I
LDO2
= 150mA, V
INLDO2
= 3.6V
I
LDO2
= 150mA, V
INLDO2
= 2.5V
I
LDO1
= 75mA, V
INLDO1
= 1.8V
160
200
170
260
320
280
mV
mV
mV
R
LDO2_PD
Output Pull-Down Resistance in Shutdown LDO2 Disabled 14 k