Datasheet

LTC1955
3
1955fd
For more information www.linear.com/LTC1955
elecTrical characTerisTics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
PVBATT
= V
SVBATT
= 3.3V, DV
CC
= 3.3V, unless otherwise noted.
PARAMETER CONDITIONS MIN TYP MAX UNITS
I
DVCC
Operating Current
l
10 25 µA
I
DVCC
Shutdown Current
l
0.5 1.5 µA
Charge Pump
R
OLCP
5V Mode Open-Loop Output Resistance V
BATT
= 3.075V, I
CPO
= I
CCA
+ I
CCB
= 120mA (Note 3)
l
5.7 8.5 Ω
CPO Turn-On Time I
CCA/B
= 0mA, 10% to 90%
l
0.6 1.5 ms
Smart Card Supplies V
CCA
, V
CCB
V
CCA/B
Output Voltage 5V Mode, 0 < I
CCA/B
< 60mA
3V Mode, 0 < I
CCA/B
< 50mA
1.8V Mode, 0 < I
CCA/B
< 30mA
l
l
l
4.65
2.75
1.65
5
3
1.8
5.35
3.25
1.95
V
V
V
V
CCA/B
Turn-On Time I
CCA/B
= 0mA, 10% to 90%
l
0.8 1.5 ms
Undervoltage Detection Relative to Nominal Output
l
–9 –5 –2.5 %
Overcurrent Detection 5V Mode
l
65 100 135 mA
Smart Card Detection
Debounce Time (
PRES A/B to D15/D7)
V
NC/NO
= 0V
l
20 35 60 ms
PRES A, PRES B Pull-Up Current V
PRESA/B
= 0
l
1.25 2.5 µA
Deactivation Time (
RST to V
CC
= 0.4V)
I
CCA/B
= 0mA, C
VCCA/B
= 1µF
l
20 250 µs
CLK A, CLK B
Low Level Output Voltage (V
OL
), (Note 2) Sink Current = –200µA
l
0.2 V
High Level Output Voltage (V
OH
), (Note 2) Source Current = 200µA
l
V
CCA/B
– 0.2 V
Rise/Fall Time (Note 2) Loaded with 50pF, 10% to 90%
l
16 ns
CLK A, CLK B Frequency (Note 2)
l
10 MHz
RST A, RST B, C4A, C8A
Low Level Output Voltage (V
OL
), (Note 2) Sink Current = –200µA
l
0.2 V
High Level Output Voltage (V
OH
), (Note 2) Source Current = 200µA
l
V
CCA/B
– 0.2 V
Rise/Fall Time (Note 2) Loaded with 50pF, 10% to 90%
l
100 ns
I/O A, I/O B
Low Level Output Voltage (V
OL
), (Note 2) Sink Current = –1mA (V
DATA
= 0V)
l
0.3 V
High Level Output Voltage (V
OH
), (Note 2) Source Current = 20µA (V
DATA
= V
DVCC
)
l
0.85 • V
CCA/B
V
Rise/Fall Time (Note 2) Loaded with 50pF, 10% to 90%
l
500 ns
Short-Circuit Current (Note 2) V
DATA
= 0V
l
5 10 mA
DATA
Low Level Output Voltage (V
OL
) Sink Current = –500µA (V
I/OA/B
= 0V)
l
0.3 V
High Level Output Voltage (V
OH
) Source Current = 20µA (V
I/OA/B
= V
CCA/B
)
l
0.8 • DV
CC
V
Rise/Fall Time Loaded with 50pF, 10% to 90%
l
500 ns
R
IN
, D
IN
, SCLK, LD, SYNC, ASYNC, NC/NO
Low Input Threshold (V
IL
)
l
0.15 • DV
CC
V
High Input Threshold (V
IH
)
l
0.85 • DV
CC
V
Input Current (I
IH
/I
IL
)
l
–1 1 µA