Datasheet

LTC2928
4
2928f
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Sequence Time Position Control Inputs: RT1, RT2, RT3, RT4 (see resistor selection Table 3)
V
RT(LO)
Voltage Required to Force Enable Pin
Low While Sequencing
●
0.045 • V
CC
V
V
RT(HI)
Voltage Required to Force Enable Pin
High Outside of Sequencing
●
0.955 • V
CC
V
R
RT
R
T
Pin Input Resistance
●
11.2 12 12.8 kΩ
Cascade Pin: CAS
V
CAS(OL)
CAS Voltage Output Low I
CAS
= 2.5mA
●
0.15 0.3 V
I
CAS(UP)
CAS Pull-Up Current Master Pulling CAS High, V
CAS
= GND
●
–45 –60 –75 µA
t
CAS(HI)
Fixed Time Delay between Sequence
Time Positions (Note 5)
CAS High, C
STMR
= 1500pF
●
11 13 15 ms
t
CAS(MIN)
Minimum CAS Low Time During
Sequencing
●
15 22.5 30 µs
Fault Status Pin: F LT
V
FLT(OL)
F LT Voltage Output Low I
FLT
= 2.5mA
●
0.15 0.3 V
I
FLT(UP)
F LT Pull-Up Current V
FLT
= V
CC
–1V
●
–12 –17 –22 µA
V
FLT(TH)
External Fault Input Threshold V
FLT
Falling
●
1.0 1.1 1.2 V
V
FLT(HYST)
External Fault Input Hysteresis ● 25 100 150 mV
t
FLT
Minimum Detectable External Fault
Pulse Width
2 µs
I
FLT(LKG)
Fault Pin Leakage Current V
FLT
= V
CC
●
± 1 µA
Done Status Pin: DONE
V
DONE(OL)
DONE Voltage Output Low I
DONE
= 2.5mA
●
0.15 0.3 V
I
DONE(DN)
DONE Pull-Down Current V
DONE
= 3.3V (Note 6)
●
20 40 µA
R
DONE
Required Pull-Up Resistance on “Last”
LTC2928
5% Tolerance or Better
●
2.4 5.1 kΩ
V
DONE(LAST)
Voltage Output High when Configured
as “Last”
●
0.8 • V
CC
V
Reset Pin: RST
V
RST(OL)
RST Voltage Output Low V
CC
= 0.2V, I
RST
= 0.1µA
V
CC
= 0.5V, I
RST
= 5µA
V
CC
= 1V, I
RST
= 200µA
V
CC
= 3V, I
RST
= 2500µA
●
●
●
●
5
10
25
150
60
150
300
300
mV
mV
mV
mV
V
RST(OH)
RST Voltage Output High I
RST
= –1µA (Note 7)
●
V
CC
– 1 V
Timer Pins: RTMR, PTMR, STMR
I
TMR(UP)
Timer Pull-Up Current V
TMR
= GND
●
–1.7 –2 –2.3 µA
I
TMR(DN)
Timer Pull-Down Current V
TMR
= 1.3V
●
15 20 25 µA
t
RTMR
t
PTMR
t
STMR
Timer Period, RTMR (Note 8)
Timer Period, PTMR
Timer Period, STMR
C
RTMR
= 1500pF
C
PTMR
= 1500pF
C
STMR
= 1500pF
●
●
●
5
5
11
6
6
13
7
7
15
ms
ms
ms
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C, V
CC
= 3.3V unless otherwise noted.