
TLC545C, TLC545I, TLC546C, TLC546I
8-BIT ANALOG-TO-DIGITAL CONVERTERS
WITH SERIAL CONTROL AND 19 INPUTS
SLAS066B – DECEMBER 1985 – REVISED OCTOBER 1996
5
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
recommended operating conditions
TLC545
TLC546
UNIT
MIN
NOM
MAX
MIN
NOM
MAX
UNIT
Supply voltage, VCC
4.75
5
5.5
4.75
5
5.5
V
Positive reference voltage, Vref+ (see Note 2)
0
VCC VCC +0.1
0
VCC VCC +0.1
V
Negative reference voltage, Vref– (see Note 3)
– 0.1
0
VCC
– 0.1
0
VCC
V
Differential reference voltage, Vref+ – Vref– (see Note 3)
0
VCC VCC +0.2
0
VCC VCC +0.2
V
Analog input voltage (see Note 3)
0
VCC
0
VCC
V
High-level control input voltage, VIH
2
V
Low-level control input voltage, VIL
0.8
V
Setup time, address bits at data input before I/O CLOCK
↑,
tsu(A)
200
400
ns
Address hold time, th
0
ns
Setup time, CS low before clocking in first address bit, tsu(CS)
(see Note 2)
3
System
clock
cycles
I/O CLOCK frequency, fclock(I/O)
0
2.048
0
1.1
MHz
SYSTEM CLOCK frequency, fclock(SYS)
fclock(I/O)
4
fclock(I/O)
2.1
MHz
Pulse duration, CS high during conversion, twH(CS)
36
System
clock
cycles
Pulse duration, SYSTEM CLOCK high, twH(SYS)
110
210
ns
Pulse duration, SYSTEM CLOCK low, twL(SYS)
100
190
ns
Pulse duration, I/O CLOCK high, twH(I/O)
200
404
ns
Pulse duration, I/O CLOCK low, twL(I/O)
200
404
ns
System
fclock(SYS) ≤ 1048 kHz
30
ns
Clock transition time
System
fclock(SYS) > 1048 kHz
20
ns
(see Note 4)
I/O
fclock(I/O) ≤ 525 kHz
100
ns
I/O
fclock(I/O) > 525 kHz
40
ns
Operating free air temperature TA
TLC545C, TLC546C
0
70
0
70
Operating free-air temperature, TA
TLC545I, TLC546I
–40
85
–40
85
°C
NOTES:
2. To minimize errors caused by noise at CS, the internal circuitry waits for three system clock cycles (or less) after a chip select falling
edge or rising edge is detected before responding to control input signals. Therefore, no attempt should be made to clock-in address
data until the minimum chip select setup time has elapsed.
3. Analog input voltages greater than that applied to REF+ convert as all “1”s (11111111), while input voltages less than that applied
to REF– convert as all “0”s (00000000). As the differential reference voltage decreases below 4.75 V, the total unadjusted error tends
to increase.
4. This is the time required for the clock input signal to fall from VIH min to VIL max or to rise from VIL max to VIH min. In the vicinity
of normal room temperature, the devices function with input clock transition time as slow as 2
s for remote data acquisition
applications where the sensor and the A/D converter are placed several feet away from the controlling microprocessor.