TLC540I, TLC541I

8-BIT ANALOG-TO-DIGITAL CONVERTERS

WITH SERIAL CONTROL AND 11 INPUTS

SLAS065A – OCTOBER 1983 – REVISED MARCH 1995

4

POST OFFICE BOX 655303

recommended operating conditions

TLC540

TLC541

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)

2.5

VCC VCC + 0.1

2.5

VCC VCC + 0.1

V

Negative reference voltage, Vref– (see Note 2)

– 0.1

0

2.5

– 0.1

0

2.5

V

Differential reference voltage, Vref+ – Vref– (see Note 2)

1

VCC VCC + 0.2

1

VCC VCC + 0.2

V

Analog input voltage (see Note 2)

0

VCC

0

VCC

V

High-level control input voltage, VIH

2

2

V

Low-level control input voltage, VIL

0.8

0.8

V

Setup time, address bits at data input before I/O CLOCK

↑,

tsu(A)

200

400

ns

Hold time, address bits after I/O CLOCK

↑,th(A)

0

0

ns

Setup time, CS low before clocking in first address bit, tsu(CS)

(see Note 3)

3

3

System

clock

cycles

CS high during conversion, twH(CS)

36

36

System

clock

cycles

I/O CLOCK frequency, fclock(I/O)

0

2.048

0

1.1

MHz

Pulse duration, SYSTEM CLOCK frequency, fclock(SYS)

fclock(I/O)

4

fclock(I/O)

2.1

MHz

Pulse duration, SYSTEM CLOCK high, twH(SYS)

110

210

MHz

Pulse duration, SYSTEM CLOCK low, twL(SYS)

100

190

MHz

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

30

Clock transition time

System

fclock(SYS) > 1048 kHz

20

20

ns

(see Note 4)

I/O

fclock(I/O) ≤ 525 kHz

100

100

ns

I/O

fclock(I/O) > 525 kHz

40

40

Operating free-air temperature, TA

TLC540I, TLC541I

–40

85

–40

85

°C

NOTES:

2. 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). For proper operation, REF+ voltage must be at least 1 V higher than REF– voltage. Also,

the total unadjusted error may increase as this differential reference voltage falls below 4.75 V.

3. 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 is detected before responding to control input signals. Therefore, no attempt should be made to clock in an address until

the minimum chip select setup time has elapsed.

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

µs for remote data acquisition

applications where the sensor and the A/D converter are placed several feet away from the controlling microprocessor.