3
LTC1555/LTC1556
V
IN
= 2.7V to 10V, DV
CC
= 1.8V to 5.5V, controller digital pins tied to DV
CC
, SIM digital pins floating, EN, FB pins tied to GND
(LTC1556), C1 = 0.1µF, C
OUT
= 10µF unless otherwise specified.
ELECTRICAL CHARACTERISTICS
over the –40°C to 85°C temperature range by design or correlation, but
are not production tested.
Note 3: The DATA and I/O pull-down drivers must also sink current
sourced by the internal pull-up resistors.
PARAMETER CONDITIONS MIN TYP MAX UNITS
V
CC
Short-Circuit Current V
CC
Shorted to GND ● 12.5 40 mA
Auxiliary LDO V
OUT
(V
LDO
) EN = High, V
CC
= 5V, FB = LDO, I
LDO
= 5mA (LTC1556) ● 4.00 4.3 4.55 V
Auxiliary Switch Resistance EN = High, V
CC
= 5V, FB = GND (LTC1556) ● 18 30 Ω
FB Input Resistance (LTC1556) 200 kΩ
Charge Pump f
OSC
● 500 650 800 kHz
Controller Inputs/Outputs, DV
CC
= 3V
Input Current (I
IH
, I
IL
) M0, M1, SS, RIN, CIN ● –1 1 µA
DDRV, EN ● –5 5 µA
High Level Input Current (I
IH
) DATA ● –20 20 µA
Low Level Input Current (I
IL
) DATA ● 1mA
High Input Voltage Threshold (V
IH
) M0, M1, RIN, CIN, DDRV, EN ● 0.7 × DV
CC
V
DATA
● DV
CC
– 0.6 V
Low Input Voltage Threshold (V
IL
) M0, M1, RIN, CIN, DDRV, EN ● 0.2 × DV
CC
V
DATA
● 0.4 V
High Level Output Voltage (V
OH
) DATA Source Current = 20µA, I/O = V
CC
● 0.7 × DV
CC
V
Low Level Output Voltage (V
OL
) DATA Sink Current = –200µA, I/O = 0V (Note 3) ● 0.4 V
DATA Pull-up Resistance Between DATA and DV
CC
● 13 20 28 kΩ
DATA Output Rise/Fall Time DATA Loaded with 30pF ● 1.3 2 µs
SIM Inputs/Outputs, DV
CC
= 3V, V
CC
= 3V or 5V
I/O High Input Voltage Threshold (V
IH
)I
IH(MAX)
= ±20µA ● 0.5 × V
CC
0.7 × V
CC
V
I/O Low Input Voltage Threshold (V
IL
)I
IL(MAX)
= 1mA ● 0.4 V
High Level Output Voltage (V
OH
) I/O, Source Current = 20µA, DATA or DDRV = DV
CC
● 0.8 × V
CC
V
RST, CLK, Source Current = 20µA
● 0.9 × V
CC
V
Low Level Output Voltage (V
OL
) I/O, Sink Current = –1mA, DATA or DDRV = 0V (Note 3) ● 0.4 V
RST, CLK, Sink Current = –200µA
● 0.4 V
I/O Pull-Up Resistance Between I/O and V
CC
● 6.5 10 14 kΩ
SIM Timing Parameters, DV
CC
= 3V, V
CC
= 5V
CLK Rise/Fall Time CLK Loaded with 30pF ● 18 ns
RST, I/O Rise/Fall Time RST, I/O Loaded with 30pF ● 1 µs
CLK Frequency CLK Loaded with 30pF ● 5 MHz
V
CC
Turn-On Time SS = DV
CC
, C
OUT
= 10µF, I
VCC
= 0 1 ms
SS = 0V, C
OUT
= 10µF, I
VCC
= 0 6 ms
V
CC
Discharge Time to 1V I
VCC
= 0, V
CC
= 5V, C
OUT
= 10µF3ms
The ● denotes specifications which apply over the specified temperature
range.
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: C grade device specifications are guaranteed over the 0°C to 70°C
temperature range. In addition, C grade device specifications are assured
