TLC0820AC, TLC0820AI
Advanced LinCMOS
TM
HIGH-SPEED 8-BIT ANALOG-TO-DIGITAL
CONVERTERS USING MODIFIED FLASH TECHNIQUES
SLAS064A SEPTEMBER 1986 REVISED JUNE 1994
21
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
D
Advanced LinCMOS
TM
Silicon-Gate
Technology
D
8-Bit Resolution
D
Differential Reference Inputs
D
Parallel Microprocessor Interface
D
Conversion and Access Time Over
Temperature Range
Read Mode . . . 2.5
s Max
D
No External Clock or Oscillator
Components Required
D
On-Chip Track and Hold
D
Single 5-V Supply
D
TLC0820A Is Direct Replacement for
National Semiconductor ADC0820C/CC and
Analog Devices AD7820K/B/T
description
The TLC0820AC and the TLC0820AI are
Advanced LinCMOS
TM
8-bit analog-to-digital
converters each consisting of two 4-bit flash
converters, a 4-bit digital-to-analog converter, a
summing (error) amplifier, control logic, and a
result latch circuit. The modified flash technique
allows low-power integrated circuitry to complete
an 8-bit conversion in 1.18
s over temperature.
The on-chip track-and-hold circuit has a 100-ns
sample window and allows these devices to
convert continuous analog signals having slew
rates of up to 100 mV/
s without external
sampling components. TTL-compatible 3-state
output drivers and two modes of operation allow
interfacing to a variety of microprocessors. Detailed information on interfacing to most popular microprocessors
is readily available from the factory.
AVAILABLE OPTIONS
TOTAL
PACKAGE
TA
TOTAL
UNADJUSTED
ERROR
SSOP
(DB)
PLASTIC
SMALL OUTLINE
(DW)
PLASTIC
CHIP CARRIER
(FN)
PLASTIC DIP
(N)
0
C to 70
C
1 LSB
TLC0820ACDB
TLC0820ACDW
TLC0820ACFN
TLC0820ACN
40
C to 85
C
1 LSB
--
TLC0820AIDW
TLC0820AIFN
TLC0820AIN
Copyright
1994, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
ANLG IN
(LSB) D0
D1
D2
D3
WR/RDY
MODE
RD
INT
GND
V
CC
NC
OFLW
D7 (MSB)
D6
D5
D4
CS
REF +
REF
DB, DW, OR N PACKAGE
(TOP VIEW)
3
2
1 20 19
9 10 11 12 13
4
5
6
7
8
18
17
16
15
14
OFLW
D7 (MSB)
D6
D5
D4
D2
D3
WR/RDY
MODE
RD
FN PACKAGE
(TOP VIEW)
D1
D0 (LSB)
ANLG IN
REF+
CS
V
NC
INT
GND
REF
NC No internal connection
CC
Advanced LinCMOS is a trademark of Texas Instruments Incorporated.
TLC0820AC, TLC0820AI
Advanced LinCMOS
TM
HIGH-SPEED 8-BIT ANALOG-TO-DIGITAL
CONVERTERS USING MODIFIED FLASH TECHNIQUES
SLAS064A SEPTEMBER 1986 REVISED JUNE 1994
22
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
functional block diagram
4
4
4
4
RD
8
CS
13
WR/RDY
6
MODE
7
ANLG IN
1
11
REF
12
REF+
+ 1
1
4-Bit Flash
Analog-to-Digital
Converter
(4 MSBs)
INT
9
Timing
and
Control
Output
Latch
and
3-State
Buffers
Digital
Outputs
D7 (MSB)
D6
D5
D4
D3
D2
D1
D0 (LSB)
OFLW
17
16
15
14
5
4
3
2
18
4-Bit
Digital-to-Analog
Converter
4-Bit Flash
Analog-to-Digital
Converter
(4 LSBs)
Summing
Amplifier
TLC0820AC, TLC0820AI
Advanced LinCMOS
TM
HIGH-SPEED 8-BIT ANALOG-TO-DIGITAL
CONVERTERS USING MODIFIED FLASH TECHNIQUES
SLAS064A SEPTEMBER 1986 REVISED JUNE 1994
23
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
Terminal Functions
TERMINAL
I/O
DESCRIPTION
NAME
NO.
I/O
DESCRIPTION
ANLG IN
1
I
Analog input
CS
13
I
Chip select. CS must be low in order for RD or WR to be recognized by the ADC.
D0
2
O
Digital, 3-state output data, bit 1 (LSB)
D1
3
O
Digital, 3-state output data, bit 2
D2
4
O
Digital, 3-state output data, bit 3
D3
5
O
Digital, 3-state output data, bit 4
D4
14
O
Digital, 3-state output data, bit 5
D5
15
O
Digital, 3-state output data, bit 6
D6
16
O
Digital, 3-state output data, bit 7
D7
17
O
Digital, 3-state output data, bit 8 (MSB)
GND
10
Ground
INT
9
O
Interrupt. In the write-read mode, the interrupt output (INT) going low indicates that the internal count-down delay
time, td(int), is complete and the data result is in the output latch. The delay time td(int) is typically 800 ns starting
after the rising edge of WR (see operating characteristics and Figure 3). If RD goes low prior to the end of td(int),
INT goes low at the end of td(RIL) and the conversion results are available sooner (see Figure 2). INT is reset by
the rising edge of either RD or CS.
MODE
7
I
Mode select. MODE is internally tied to GND through a 50-
A current source, which acts like a pulldown resistor.
When MODE is low, the read mode is selected. When MODE is high, the write-read mode is selected.
NC
19
No internal connection
OFLW
18
O
Overflow. Normally OFLW is a logical high. However, if the analog input is higher than Vref+, OFLW will be low at
the end of conversion. It can be used to cascade two or more devices to improve resolution (9 or 10 bits).
RD
8
I
Read. In the write-read mode with CS low, the 3-state data outputs D0 through D7 are activated when RD goes
low. RD can also be used to increase the conversion speed by reading data prior to the end of the internal
count-down delay time. As a result, the data transferred to the output latch is latched after the falling edge of RD.
In the read mode with CS low, the conversion starts with RD going low. RD also enables the 3-state data outputs
on completion of the conversion. RDY going into the high-impedance state and INT going low indicate completion
of the conversion.
REF
11
I
Reference voltage. REF is placed on the bottom of the resistor ladder.
REF +
12
I
Reference voltage. REF + is placed on the top of the resistor ladder.
VCC
20
Power supply voltage
WR/RDY
6
I/O
Write ready. In the write-read mode with CS low, the conversion is started on the falling edge of the WR input signal.
The result of the conversion is strobed into the output latch after the internal count-down delay time, td(int), provided
that the RD input does not go low prior to this time. The delay time td(int) is approximately 800 ns. In the read mode,
RDY (an open-drain output) goes low after the falling edge of CS and goes into the high-impedance state when
the conversion is strobed into the output latch. It is used to simplify the interface to a microprocessor system.
TLC0820AC, TLC0820AI
Advanced LinCMOS
TM
HIGH-SPEED 8-BIT ANALOG-TO-DIGITAL
CONVERTERS USING MODIFIED FLASH TECHNIQUES
SLAS064A SEPTEMBER 1986 REVISED JUNE 1994
24
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Supply voltage, V
CC
(see Note 1)
10 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage range, all inputs (see Note 1)
0.2 V to V
CC
+ 0.2 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output voltage range, all outputs (see Note 1)
0.2 V to V
CC
+ 0.2 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating free-air temperature range: TLC0820AC
0
C to 70
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TLC0820AI 40
C to 85
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range
65
C to 150
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Case temperature for 10 seconds: FN package
260
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds: DB, DW or N package
260
C
. . . . . . . . . . .
Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTE 1: All voltages are with respect to network GND.
recommended operating conditions
MIN
NOM
MAX
UNIT
Supply voltage, VCC
4.5
5
8
V
Analog input voltage
0.1
VCC + 0.1
V
Positive reference voltage, Vref +
Vref
VCC
V
Negative reference voltage, Vref
GND
Vref+
V
High level input voltage VIH
VCC = 4 75 V to 5 25 V
CS, WR/RDY, RD
2
V
High-level input voltage, VIH
VCC = 4.75 V to 5.25 V
MODE
3.5
V
Low level input voltage VIL
VCC = 4 75 V to 5 25 V
CS, WR/RDY, RD
0.8
V
Low-level input voltage, VIL
VCC = 4.75 V to 5.25 V
MODE
1.5
V
Pulse duration, write in write-read mode, tw(W) (see Figures 2, 3, and 4)
0.5
50
s
Operating free air temperature TA
TLC0820AC
0
70
C
Operating free-air temperature, TA
TLC0820AI
40
85
C
TLC0820AC, TLC0820AI
Advanced LinCMOS
TM
HIGH-SPEED 8-BIT ANALOG-TO-DIGITAL
CONVERTERS USING MODIFIED FLASH TECHNIQUES
SLAS064A SEPTEMBER 1986 REVISED JUNE 1994
25
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
electrical characteristics at specified operating free-air temperature, V
CC
= 5 V (unless otherwise
noted)
PARAMETER
TEST CONDITIONS
TA
MIN
TYP
MAX
UNIT
V
Hi h l
l
t
t
lt
D0 D7, INT, or
VCC = 4.75 V,
IOH = 360
A
Full range
2.4
V
VOH
High-level output voltage
D0 D7, INT, or
OFLW
VCC = 4.75 V,
Full range
4.5
V
CC
,
IOH = 10
A
25
C
4.6
VOL
Low level output voltage
D0 D7, OFLW, INT,
VCC = 5.25 V,
Full range
0.4
V
VOL
Low-level output voltage
D0 D7, OFLW, INT,
or WR/RDY
CC
,
IOL = 1.6 mA
25
C
0.34
V
CS or RD
Full range
0.005
1
WR/RDY
Full range
3
IIH
High-level input current
WR/RDY
VIH = 5 V
25
C
0.1
0.3
A
MODE
Full range
200
MODE
25
C
50
170
IIL
Low-level input current
CS, WR/RDY, RD,
or MODE
VIL = 0
Full range
0.005
1
A
VO = 5 V
Full range
3
IOZ
Off-state (high-impedance-state)
D0 D7 or WR/RDY
VO = 5 V
25
C
0.1
0.3
A
IOZ
( g
)
output current
D0 D7 or WR/RDY
VO = 0
Full range
3
A
VO = 0
25
C
0.1
0.3
CS at 5 V
VI = 5 V
Full range
3
II
Analog input current
CS at 5 V,
VI = 5 V
25
C
0.3
A
II
Analog input current
CS at 5 V
VI = 0
Full range
3
A
CS at 5 V,
VI = 0
25
C
0.3
D0 D7, OFLW, INT,
VO = 5 V
Full range
7
D0 D7, OFLW, INT,
or WR/RDY
VO = 5 V
25
C
8.4
14
IOS
Short circuit output current
D0 D7 or OFLW
Full range
6
mA
IOS
Short-circuit output current
D0 D7 or OFLW
VO = 0
25
C
7.2
12
mA
INT
VO = 0
Full range
4.5
INT
25
C
5.3
9
R f
Reference resistance
Full range
1.25
6
k
Rref
Reference resistance
25
C
1.4
2.3
5.3
k
ICC
Supply current
CS, WR/RDY, and
Full range
15
mA
ICC
Supply current
CS, WR/RDY, and
RD at 0 V
25
C
7.5
13
mA
Ci
Input capacitance
D0 D7
Full range
5
pF
Ci
Input capacitance
ANLG IN
Full range
45
pF
Co
Output capacitance
D0 D7
Full range
5
pF
Full range is as specified in recommended operating conditions.
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