1
May 1997
ML2264
*
4-Channel High-Speed 8-Bit
A/D Converter with T/H (S/H)
GENERAL DESCRIPTION
The ML2264 is a high-speed, P compatible, 4-channel
8-bit A/D converter with a conversion time of 680ns over
the operating temperature range and supply voltage
tolerance. The ML2264 operates from a single 5V supply
and has an analog input range from GND to V
CC
.
The ML2264 has two different pin selectable modes. The
T/H mode has an internal track and hold. The S/H mode
has a true internal sample and hold and can digitize 0 to
5V sinusoidal signals as high as 500kHz.
The ML2264 digital interface has been designed so that
the device appears as a memory location or I/O port to a
P. Analog input channels are selected by the latched and
decoded multiplexer address inputs.
The ML2264 is an enhanced, pin compatible second
source for the industry standard AD7824. The ML2264
enhancements are faster conversion time, parameters
guaranteed over the supply tolerance and temperature
range, improved digital interface timing, superior power
supply rejection, and better latchup immunity on analog
inputs.
FEATURES
s
Conversion time, WR-RD mode over temperature and
supply voltage tolerance
Track & Hold Mode ................................. 830ns max
Sample & Hold Mode .............................. 700ns max
s
Total unadjusted error ..................... 1/2 LSB or 1 LSB
s
Capable of digitizing a 5V, 250kHz sine wave
s
4-analog input channels
s
No missing codes
s
0V to 5V analog input range with single 5V power
supply
s
No zero or full scale adjust required
s
Analog input protection ............................... 25mA min
s
Operates ratiometrically or with up to 5V voltage
reference
s
No external clock required
s
Power-on reset circuitry
s
Low power ....................................................... 100mW
s
Narrow 24-pin DIP, SOIC, or SSOP
s
Superior pin compatible replacement for AD7824
BLOCK DIAGRAM
PIN CONNECTIONS
A IN 1
A IN 2
A IN 3
A IN 4
4-CH
MUX
ADDRESS
LATCH
DECODE
A0
A1
TIMING
&
CONTROL
INT
CS WR/RDY RD SH/TH MODE
4-BIT
FLASH
A/D
(MSB)
V
CC
+V
REF
V
REF
GND
SH/TH
+
SAMPLE
&
HOLD
4-BIT
D/A
4-BIT
FLASH
A/D
(LSB)
V
REF
+V
REF
16
V
REF
16
DB7
DB6
DB5
DB4
DB3
DB2
DB1
DB0
DECODE
LOGIC,
LATCH
&
THREE
STATE
OUTPUT
BUFFER
+V
REF
V
REF
+V
REF
TOP VIEW
A IN 4
A IN 3
A IN 2
A IN 1
MODE
DB0
DB1
DB2
DB3
RD
INT
GND
V
CC
SH/TH
A0
A1
DB7
DB6
DB5
DB4
CS
WR/RDY
+V
REF
V
REF
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
A IN 4
A IN 3
A IN 2
A IN 1
MODE
DB0
DB1
DB2
DB3
RD
INT
GND
V
CC
SH/TH
A0
A1
DB7
DB6
DB5
DB4
CS
WR/RDY
+V
REF
V
REF
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
TOP VIEW
24-Pin DIP
24-Pin SOIC
24-Pin SSOP
*This Part Is End Of Life As Of August 1, 2000
ML2264
2
PIN# NAME
FUNCTION
PIN# NAME
FUNCTION
1
A IN 4
Analog input 4.
2
A IN 3
Analog input 3.
3
A IN 2
Analog input 2.
4
A IN 1
Analog input 1.
5
MODE
Mode select input.
MODE = GND: RD mode
MODE = V
CC
: WR-RD mode
Pin has internal current source
pulldown to GND.
6
DB0
Data output -- bit 0 (LSB).
7
DB1
Data output -- bit 1.
8
DB2
Data output -- bit 2.
8
DB3
Data output -- bit 3.
10 RD
Read input. In RD mode, this pin
initiates a conversion. In WR-RD
mode, this pin latches data into output
latches. See Digital Interface section.
11 INT
Interrupt output. This output signals
the end of a conversion and indicates
that data is valid on the data outputs.
See Digital Interface section.
12 GND
Ground.
13 V
REF
Negative reference voltage for
A/D converter.
14 +V
REF
Positive reference voltage for
A/D converter.
PIN DESCRIPTION
15 WR/RDY
Write input or ready output. In WR-RD
mode, this pin is WR input. In RD
mode, this pin is RDY open drain
output. See Digital Interface section.
16 CS
Chip select input. This pin must be
held low for the device to perform a
conversion.
17 DB4
Data output -- bit 4.
18 DB5
Data output -- bit 5.
19 DB6
Data output -- bit 6.
20 DB7
Data output -- bit 7 (MSB).
21 A1
Digital address input 1 that selects
analog input channel. See multiplexer
addressing section.
22 A0
Digital address input 0 that selects
analog input channel. See multiplexer
addressing section.
23 SH/TH
S/H, T/H mode select. When SH/TH =
V
CC
, the device is in sample and hold
mode. When SH/TH = GND, the
device is in track and hold mode. Pin
has internal pulldown current source
to GND.
24 V
CC
Positive supply. +5 volts 5%.
ABSOLUTE MAXIMUM RATINGS
Absolute maximum ratings are those values beyond which
the device could be permanently damaged. Absolute
maximum ratings are stress ratings only and functional
device operation is not implied.
Supply Voltage, V
CC
................................................. 6.5V
Voltage
Logic Inputs ................................. 0.3V to V
CC
+ 0.3V
Analog Inputs .............................. 0.3V to V
CC
+ 0.3V
Input Current per Pin (Note 2) .............................. 25mA
Storage Temperature .............................. 65C to +150C
Package Dissipation
at T
A
= 25C (Board Mount) ............................. 875mW
Lead Temperature (Soldering 10 sec.)
Dual-In-Line Package (Plastic) ............................ 260C
Dual-In-Line Package (Ceramic) ......................... 300C
SOIC
Vapor Phase (60 sec.) ..................................... 215C
Infrared (15 sec.) ............................................ 220C
OPERATING CONDITIONS
Supply Voltage, V
CC
............................ 4.5V
DC
to 6.0V
DC
Temperature Range (Note 3) ................. T
MIN
- T
A
- T
MAX
ML2264CCS
ML2264CCP
ML2264CCR ........................................... 0C to +70C
ML2264
3
ELECTRICAL CHARACTERISTICS
Unless otherwise specified, T
A
= T
MIN
to T
MAX
, V
CC
= +V
REF
= 5V 5%, and V
REF
= GND (Note 1)
ML2264XCX
TYP
PARAMETER
NOTES
CONDITIONS
MIN
(NOTE 3)
MAX
UNITS
Converter
Total Unadjusted Error
ML2264CXX
4, 6
1
LSB
Integral Linearity Error
ML2264CXX
4, 6
1
LSB
Differential Linearity Error
ML2264CXX
4
1
LSB
Full Scale Error
ML2264CXX
4
1
LSB
Zero Scale Error
ML2264CXX
4
1
LSB
Channel to Channel Mismatch
4
1/4
LSB
+V
REF
Voltage Range
5
V
REF
V
CC
+0.1
V
V
REF
Voltage Range
5
GND0.1
+V
REF
V
Reference Input Resistance
4
1
2.5
4
k
Analog Input Range
4, 7
GND0.1
V
CC
+0.1
V
Power Supply Sensitivity
4
DC
1/32
1/4
LSB
V
CC
=5V 5%, V
REF
= 4.50V
100mVp-p
1/16
LSB
100kHz sine on V
CC
, V
IN
= 0
Analog Input Leakage Current,
4
ON Channel = V
CC
1
A
OFF Channel
OFF Channel = 0V
ON Channel = 0V
1
A
OFF Channel = V
CC
Analog Input Leakage Current,
4
ON Channel = 0V
1
A
ON Channel
OFF Channel = V
CC
ON Channel = V
CC
1
A
OFF Channel = 0V
Analog Input Capacitance
During Acquisition Period
45
pF
Digital and DC
V
IN(1)
, Logical "1" Input Voltage
4
WR, RD, CS, A0, A1
2.0
V
MODE, SH/TH
V
CC
0.5
V
V
IN(0)
, Logical "0" Input Voltage
4
WR, RD, CS, A0, A1
0.8
V
MODE, SH/TH
0.5
V
I
IN(1)
, Logical "1" Input Current
4
V
IH
= V
CC
WR, RD, CS, A0, A1
1
A
MODE, SH/TH
15
50
150
A
I
IN(0)
, Logical "0" Input Current
4
V
IL
= GND
WR, RD, CS
1
A
MODE, SH/TH
20
A
ML2264
4
ELECTRICAL CHARACTERISTICS
(Continued)
Unless otherwise specified, T
A
= T
MIN
to T
MAX
, V
CC
= +V
REF
= 5V 5%, and V
REF
= GND, and timing measured at 1.4V,
C
L
= 100pF. (Note 1)
ML2264XCX
TYP
PARAMETER
NOTES
CONDITIONS
MIN
(NOTE 3)
MAX
UNITS
Digital and DC (Continued)
V
OUT(1)
, Logical "1"
4
I
OUT
= 2mA
4.0
V
Output Voltage
V
OUT(0)
, Logical "0"
4
I
OUT
= 2mA
0.4
V
Output Voltage
I
OUT
, Three-State Output
4
V
OUT
= 0V
1
A
Current
V
OUT
= V
CC
1A
C
OUT
, Logic Output
5
pF
Capacitance
C
IN
, Logic Input
5
pF
Capacitance
I
CC
, Supply Current
4
CS = WR = RD = "1",
18
mA
No Output Load
AC and Dynamic Performance (Note 9)
t
CRD
, Conversion Time,
4
RD to INT, MODE = 0V
1020
ns
Read Mode
t
CWR-RD
, Conversion Time,
4, 8
WR Falling
SH/TH = V
CC
700
ns
Write-Read Mode
Edge to INT,
t
RD
< t
INT
,
SH/TH = GND
830
ns
MODE = V
CC
SNR, Signal to Noise Ratio
V
IN
= 5V, 250kHz
48
dB
Noise is sum of all nonfundamental
components from 0500kHz.
SH/TH = V
CC
, MODE = V
CC
f
SAMPLING
= 1.0 MHz
HD, Harmonic Distortion
V
IN
= 5V, 250kHz
63
dB
THD is sum of 25th harmonics relative to
fundamental.
SH/TH = V
CC
, MODE = V
CC
f
SAMPLING
= 1.0 MHz
IMD, Intermodulation Distortion
fa = 2.5V, 250kHz
60
dB
fb = 2.5V, 248kHz
IMB is (fa + fb), (fa fb), (2fa + fb), (2fa fb),
(fa + 2fb), or (fa 2fb) relative to fundamental.
SH/TH = V
CC
, MODE = V
CC
f
SAMPLING
= 1.0 MHz
FR, Frequency Response
V
IN
= 5V, 0250kHz Relative to 1kHz
0.1
dB
SH/TH = V
CC
, MODE = V
CC
f
SAMPLING
= 1.0 MHz
SR, Slew Rate Tracking
5
SH/TH = V
CC
4.0
V/s
SH/TH = GND
0.25
V/s
t
AS
, Multiplexer Address
4
SH/TH = GND, Figure 1
0
ns
Setup Time
(Track & Hold Operation)
ML2264
5
ELECTRICAL CHARACTERISTICS
(Continued)
Unless otherwise specified, T
A
= T
MIN
to T
MAX
, V
CC
= +V
REF
= 5V 5%, and V
REF
= GND, and timing measured at 1.4V,
C
L
= 100pF. (Note 1)
ML2264XCX
TYP
PARAMETER
NOTES
CONDITIONS
MIN
(NOTE 3)
MAX
UNITS
AC and Dynamic Performance (Note 9) (Continued)
t
AH
, Multiplexer Address
4
SH/TH = GND, Figure 1
60
ns
Hold Time
(Track & Hold Operation)
t
AS
, Multiplexer Address
4
SH/TH = V
CC
, Figure 2
225
ns
Setup Time
(Sample & Hold Operation)
t
AH
, Multiplexer Address
4
SH/TH = V
CC
, Figure 2
60
ns
Hold Time
(Sample & Hold Operation)
AC Performance Read Mode (Pin 5 = 0V), Figure 4
t
RDY
, CS to RDY Delay
4
0
60
ns
t
RDD
, RD Low to RDY Delay
4, 9
Figure 3
1020
ns
t
CSS
, CS to RD, WR Setup Time
4
0
ns
t
CSH
, CS to RD, WR Hold Time
4
0
ns
t
CRD
, Conversion Time --
4, 9
1020
ns
RD Low to INT low
t
ACC0
, Data Access Time
4
t
CRD
10
t
CRD
+20
ns
RD to Data Valid
t
RDPW
, RD Pulse Width
4
t
CRD
+30
ns
t
INTH
, RD to INT Delay
4, 9
0
65
ns
t
DH
, Data Hold Time --
5, 9
Figure 3
0
50
ns
RD Rising Edge to Data
High Impedance State
t
P
, Delay Time Between
4, 9
Sample & Hold Mode,
300
ns
Conversions -- INT Low
SH/TH = V
CC
to RD Low
Track & Hold Mode,
240
ns
SH/TH = GND
AC Performance Write-Read Mode (Pin 5 = 5V), Figures 5 and 6
t
CSS
, CS to RD, WR Setup Time
4
0
ns
t
CSH
, CS to RD, WR Hold Time
4
0
ns
t
WR
, WR Pulse Width
4
SH/TH = V
CC
190
50K
ns
5
SH/TH = GND
320
50K
ns
t
RD
, Read Time -- WR
4
t
RD
< t
INTL
275
ns
High to RD Low Delay
t
RI
, RD to INT Delay
4, 9
t
RD
< t
INTL
0
235
ns
t
ACC1
, Data Access Time
4
t
RD
< t
INTL
0
240
ns
-- RD Low to Data Valid
t
CWR-RD
, Conversion Time
4, 8, 9
t
RD
< t
INTL
, SH/TH = V
CC
700
ns
-- WR Falling Edge to INT Low
5, 8, 9
t
RD
< t
INTL
, SH/TH = GND
830
ns
PDF 
ZIP