Linear Technology LTC3558, Manual

Page: 4 / 32

LTC3558
4
3558f
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Logic (HPWR, SUSP,
CHRG
, EN1, EN2, MODE)
V
IL
Input Low Voltage HPWR, SUSP, MODE, EN1, EN2 Pins 0.4 V
V
IH
Input High Voltage HPWR, SUSP, MODE, EN1, EN2 Pins 1.2 V
R
DN
Logic Pin Pull-Down Resistance HPWR, SUSP Pins
l
1.9 4 6.3
M
Ω
V
CHRG
CHRG
Pin Output Low Voltage I
CHRG
= 5mA 100 250 mV
I
CHRG
CHRG
Pin Input Current BAT = 4.5V, V
CHRG
= 5V 0 1 μA
Buck Switching Regulator
PV
IN1
Input Supply Voltage
l
2.7 4.2 V
I
PVIN1
Pulse Skip Input Current
Burst Mode Current
Shutdown Current
Supply Current in UVLO FB1 = 0.85V, MODE = 0 (Note 6)
FB1 = 0.85V, MODE = 1 (Note 6)
EN1 = 0
PV
IN1
= PV
IN2
= 2V
l
220
35
0
4
400
50
2
8
μA
μA
μA
μA
PV
IN1
UVLO PV
IN1
Falling
PV
IN1
Rising
l
l
2.30 2.45
2.55
2.70
V
V
f
OSC
Switching Frequency MODE = 0 1.91 2.25 2.59 MHz
I
LIMSW1
Peak PMOS Current Limit 550 800 1050 mA
V
FB1
Feedback Voltage MODE = 0
l
780 800 820 mV
I
FB1
FB Input Current FB1 = 0.85V –50 50 nA
D
MAX1
Maximum Duty Cycle FB1 = 0V
l
100 %
R
PMOS1
R
DS(ON)
of PMOS I
SW1
= 100mA 0.65
Ω
R
NMOS1
R
DS(ON)
of NMOS I
SW1
= –100mA 0.75
Ω
R
SW1(PD)
SW Pull-Down in Shutdown 13
k
Ω
Buck-Boost Switching Regulator
PV
IN2
Input Supply Voltage
l
2.7 4.2 V
I
PVIN2
PWM Input Current
Burst Mode Input Current
Shutdown Current
Supply Current in UVLO MODE = 0, I
OUT
= 0A, FB2 = 0.85V (Note 6)
MODE = 1, I
OUT
= 0A, FB2 = 0.85V (Note 6)
EN2 = 0, I
OUT
= 0A
PV
IN1
= PV
IN2
= 2V
220
20
0
4
400
30
1
8
μA
μA
μA
μA
PV
IN2
UVLO PV
IN2
Falling
PV
IN2
Rising
l
l
2.30 2.45
2.55
2.70
V
V
V
OUT2(LOW)
Minimum Regulated Buck-Boost V
OUT
2.65 2.75 V
V
OUT2(HIGH)
Maximum Regulated Buck-Boost V
OUT
5.45 5.60 V
I
LIMF2
Forward Current Limit (Switch A) MODE = 0
l
580 700 820 mA
I
PEAK2(BURST)
Forward Current Limit (Switch A) MODE = 1
l
180 250 320 mA
I
LIMR2
Reverse Current Limit (Switch D) MODE = 0
l
325 450 575 mA
I
ZERO2(BURST)
Reverse Current Limit (Switch D) MODE = 1
l
–35 0 35 mA
I
MAX2(BURST)
Maximum Deliverable Output Current
in Burst Mode Operation 2.7V < PV
IN2
< 4.2V
2.75V < V
OUT2
< 5.5V
50 mA
V
FB2
Feedback Servo Voltage
l
780 800 820 mV
I
FB2
FB2 Input Current FB2 = 0.85V –50 50 nA
f
OSC
Switching Frequency MODE = 0 1.91 2.25 2.59 MHz
ELECTRICAL CHARACTERISTICS
The
l
denotes specifi cations that apply over the full operating temperature
range, otherwise specifi cations are at T
A
= 25°C. V
CC
= 5V, BAT = PV
IN1
= PV
IN2
= 3.6V, R
PROG
= 1.74k, unless otherwise noted.