Datasheet

LTC1955
4
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
D
OUT
Low Level Output Voltage (V
OL
) Sink Current = –200µA
l
0.3 V
High Level Output Voltage (V
OH
) Source Current = 200µA
l
DV
CC
– 0.3 V
UNDERV
Threshold
l
1.17 1.23 1.29 V
Leakage Current V
UNDERV
= 3.3V
l
50 nA
FAULT
Low Level Output Voltage (V
OL
) Sink Current = –200µA
l
0.005 0.3 V
Leakage Current V
FAULT
= 5.5V
l
1 µA
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: This specification applies to all three smart card voltage classes:
1.8V, 3V and 5V.
Note 3: R
OLCP
@ (2V
BATT
– V
CPO
)/I
CPO
; V
CPO
will depend upon total load
(I
CCA
+ I
CCB
) and minimum supply voltage V
BATT
. See Figure 5.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Serial Port Timing
t
DS
D
IN
Valid to SCLK Setup
l
8 ns
t
DH
D
IN
Valid to SCLK Hold
l
8 ns
t
DD
D
OUT
Output Delay C
LOAD
= 15pF
l
15 60 ns
t
L
SCLK Low Time
l
50 ns
t
H
SCLK High Time
l
50 ns
t
CL
SCLK to LD
l
50 ns
t
LC
LD to SCLK
l
0 ns
t
LFC
LD Falling to SCLK
l
50 ns
Note 4: The LTC1955E is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°C to 85°C operating
ambient temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC1955I is guaranteed to
meet performance specifications over the full –40°C to 85°C temperature
range.