Datasheet ALD1801DC, ALD1801BSC, ALD1801BPC, ALD1801BDC, ALD1801ASC Datasheet (Advanced Linear Devices Inc)

ADVANCED
LINEAR
DEVICES, INC.

ALD1801A/ALD1801B

ALD1801

8 BIT MICROPOWER MULTIPLYING D/A CONVERTER

GENERAL DESCRIPTION

The ALD1801 is an 8-bit monolithic current output digital to analog
converter designed to provide low power, low operating voltage and simple
operation. It offers industry pin configuration of DAC-08 types, and is
intended for a wide range of digital to analog conversion and control
applications in +5V single power supply and ±5V dual power supply
systems, as well as +3V to +12V battery operated systems. Device
characteristics are specified for +5V single supply and 3.3V dual supply
systems.

The ALD1801 is manufactured with Advanced Linear Devices’ enhanced
ACMOS silicon gate CMOS process and has been designed to be also
used as a linear cell element in Advanced Linear Devices’ "Function­Specific" ASIC, as it is fully compatible in design, operation, and manufacture
with all other linear elements in Advanced Linear Devices’ product family.

The ALD1801 is designed with matching between reference and full scale
currents. Digital inputs are standard CMOS logic inputs to provide ease
of interface. Output currents can be directly converted to a voltage output
by using a pair of resistors. When used with ALD’s rail-to-rail output
operational amplifiers such as the ALD1702, full scale output of 0 to +5V
can be easily achieved with single +5V power supply.

ORDERING INFORMATION

Operating Temperature Range

-55°C to +125°C0°C to +70°C0°C to +70°C
16-Pin 16-Pin 16-Pin

CERDIP Small Outline Plastic Dip
Package Package(SOIC) Package

ALD1801A DC ALD1801A SC ALD1801A PC
ALD1801B DC ALD1801B SC ALD1801B PC
ALD1801 DC ALD1801 SC ALD1801 PC

FEATURES

• Low voltage 3V to 12V operation

• Low power 1.8mW max @ 3.3V

• Single supply operation (5V or 3.3V)

• Direct CMOS logic interface

• Complementary current outputs

• Nonlinearity to 0.1% max over
temperature range

• High input impedance

• Low full scale current

• High output impedance

PIN CONFIGURATION

1

N/C N/C

I OUT

MSB B

2

-

V

3

I

4

OUT

5

1

6

B

2

B

7

3

8

B

4

TOP VIEW

DC, PC, SC PACKAGE

* N/C Pin is connected internally. Do not connect externally.

16

15

14

13

12

11

10

9

V

REF-

V

REF+

+

V

B8 LSB

B

7

B

6

B

5

* Contact factory for industrial temperature range

BLOCK DIAGRAM

IOUT

4
2

V

REF+

14

V

REF-

15

© 1998 Advanced Linear Devices, Inc. 415 T asman Drive, Sunnyvale, California 94089 -1706 Tel: [phone] Fax: [phone] http://www .aldinc.com

V+

13

I

B1

3

5

B

1

MSB

I

B2

6

B

2

I

B3

7

B

3

I

B4

8

B

4

I

B5

9

B

5

I

B6

10

B

6

I

B7

11

B

7

12

B

8

LSB

IOUT

I

B8

OPERATING ELECTRICAL CHARACTERISTICS

= 25°C VS = ±2.5V or VS = +5.0V unless otherwise specifie

T

A

1801A 1801B 1801
Parameter Symbol Min Typ Max Min Typ Max Min Typ Max Unit Test Conditions

Supply V
Voltage Single Supply

S

Resolution 8 8 8 Bits
Monotonicity 8 8 8 Bits

±1.5 ±6.0 ±1.5 ±6.0 ±1.5 ±6.0 V Dual Supply

Nonlinearity N

Settling Time t

Propagation t
Delay 1.5 2.5 1.5 2.5 1.5 2.5 µs All Bits

Full Scale T
Tempco

Output V
Compliance +1.5 +0.2 +1.5 +0.2 +1.5 +0.2

L

S

d

C

-

OC

V

±0.1 ±0.19 ±0.39 % of

Full Scale

2.5 5.0 2.5 5.0 2.5 5.0 µs To 1/2 LSB with all bits
turned on/off

1.5 2.5 1.5 2.5 1.5 2.5 µs Each Bit

±10 ±50 ±10 ±50 ±10 ±50 ppm/°C

V+V

-

V+V

-

V+V

Output 50 50 50 MΩ Output Within
Impedance Compliance limits

Full Scale I
Current Range V

Full Scale I
Symmetry

Zero Scale I
Current

Logic Input Level
Logic "0" V
Logic "1" V

FS

FSS

ZS

1

IL
IH

100 100 100 µAR

±2.5 ±2.5 ±2.5 µA

10 10 10 nA

-1.1 -1.1 -1.1 V Supply = ±2.5V

2.1 2.1 2.1

OUT

REF

= R

OUT

= 2.5V; R

Logic Swing
Logic Threshold V
Range -1.5 1.5 -1.5 1.5 -1.5 1.5 V Supply = ±2.5V

LS

-2.8 2.8 -2.8 2.8 -2.8 2.8 V Supply = ±2.5V

= 50KΩ

=25KΩ

REF

Reference Bias I
Current

Power Supply +I
Current - I

Power Dissipation P

RB

S
S

D

0.1 0.1 0.1 nA

500 800 500 800 500 800 µA Full Scale
700 1000 700 1000 700 1000 Output = 100µA

4.5 4.5 4.5 mW Supply = ±2.5V

Compensation Not Required

Notes: 1. Contact ALD for ±1.0V/±1.25V operation

2. Logic levels of V

0.4V and VIH 4.6V for single supply applications.

IL

ALD1801A/ALD1801B Advanced Linear Devices 2
ALD1801

OPERATING ELECTRICAL CHARACTERISTICS
T

= 25°C VS = ±1.65V or VS = +3.3V unless otherwise specified

A

1801A 1801B 1801
Parameter Symbol Min Typ Max Min Typ Max Min Typ Max Unit Test Conditions

Resolution 8 8 8 Bits

Monotonicity 8 8 8 Bits

Nonlinearity N

Settling Time t

L

S

±0.1 ±0.19 ±0.39 % of

Full Scale

4.0 10.0 4.0 10.0 4.0 10.0 µs To 1/2 LSB with all bits
turned on/off

Propagation t

d

1.5 4.0 1.5 4.0 1.5 4.0 µs Each Bits

Delay 1.5 4.0 1.5 4.0 1.5 4.0 µs All Bits

Full Scale T

C

±10 ±50 ±10 ±50 ±10 ±50 ppm/°C

Tempco

Output V

OC

-

V

V+V

-

V+V

-

V+V

Compliance +1.5 +0.2 +1.5 +0.2 +1.5 +0.2

Output 50 50 50 MΩ Output Within
Impedance Compliance limits

Full Scale I

FS

50 50 50 µAR

Current Range V

Full Scale I

FSS

±2.5 ±2.5 ±2.5 µA

OUT
REF

= R

OUT

= 2.5V; R

= 100KΩ

Symmetry

Zero Scale I

ZS

10 10 10 nA

Current

REF

=50KΩ

Reference Bias I

RB

0.1 0.1 0.1 nA

Current

Power Supply +I
Current - I

Power Dissipation P

S
S

D

350 500 350 500 350 500 µA Full Scale
450 600 450 600 450 600 Output = 50µA

1.8 1.8 1.8 mW

ALD1801A/ALD1801B Advanced Linear Devices 3
ALD1801

+V

DUAL SUPPLY ±2.5V

RATIOMETRIC VOLTAGE OUTPUT DAC

50K

V+ = 2.5V

50K

REF

ALD
1702

­+

V- = 2.5V
V+ = 2.5V

13

15
14

12
11
10

9

B1
B2
B3
B4

34

2

5
6
7
8

ALD 1801

V

B8
B7
B6
B5

V

OUT

REF-

LSB

25K

+V

REF

=2.5V

Zero Scale 0 0 0 00000-2.500

B1 B2 B3 B4 B5 B6 B7 B8 V

LSB 00000001-2.480
Half Scale -LSB 0 1 1 11111 -0.019
Half Scale 1 0 0 000000.000
Half Scale +LSB 1 0 0 000010.019
Full Scale 1 1 1 111112.480

OUT

SINGLE SUPPLY 3.3V

RATIOMETRIC VOLTAGE OUTPUT DAC

50K

50K

V+

V+ = 3.3V

­+

V

OUT

1/2 ALD2701

50K

50K

1/2 ALD2701

­+

MSB

0.1µF

B1
B2
B3
B4

2

5
6
7
8

V+

13

34

15

25K

14

+V

= V+

REF

B8
B7
B6
B5

LSB

12
11
10

9

ALD 1801

Zero Scale 0 0 0 000000.000

B1 B2 B3 B4 B5 B6 B7 B8 V

Half Scale 1 0 0 000001.650
Full Scale 1 1 1 111113.287

ALD1801A/ALD1801B Advanced Linear Devices 4
ALD1801

OUT

APPLICATIONS NOTES:

The ALD1801 is an 8 bit multiplying D/A converter. It has
been designed to operate with standard single or split
power supplies of 5V or ±5V. Functionality extends down
to 3V or ±1.5V power supply, making it ideal for lithium
battery or rechargeable battery operated systems where
power efficiency and performance are important design
parameters.

The ALD1801 features ultra low quiescent bias current
which depends on the operating current in the internal
current steering circuit. A high gain internal operational
amplifier is fully compensated for stable operation without
any need for external capacitor compensation. The
operational amplifier is placed in a negative feedback loop
to generate the reference current for ratio matched
transistors. It is trimmed to provide nonlinearity as
specified. In some applications this feature can be used
along with the multiplying nature of the ALD1801 to obtain
9 or 10 bit digital to analog conversion with external
switches.

The ALD1801 is a multiplying D/A converter in which the
output is a current that is a function of an 8 bit digital input
word multiplied by the reference current. The reference
current may be a fixed reference current or a varying input
current. If a fixed reference voltage or a varying low
impedance voltage output source is used, a fixed value
resistor (referred to as RREF) can be used to convert
the voltage into a reference current for most applications.

is a precision fixed resistor without trimming.

R

REF

Trimming can be accomplished by adjusting R

REF

through
either connecting a potentiometer in series with a fixed
resistor or by substituting the fixed resistor with a multi­turn potentiometer. The recommended nominal value of

is 25KΩ.

R

REF

The ALD1801 can operate from single power supply or
dual supplies up to ±6.6V. Symmetrical supplies are not
required in the case of dual supply operation. However,

input voltage must be set at 1V or higher above the

V

-

REF

V- voltage. Due to the internal operational amplifier
feedback, V
potential as V

input terminal would be set at the same

+

REF

- input terminal, with the input reference

REF

current determined by: Input reference current

I

REF

= { (V

REF+

)- (V

REF-

) } / R

REF

The ALD1801 is fabricated in CMOS technology and
provides direct logic interface to all CMOS logic families
including logic levels of the CD4000 and 74C logic families
operating at logic voltage levels other than 5V. It is
primarily designed to operate in a power supply
environment where interface takes place between digital
logic circuitry and analog circuitry. Both types of circuitry
operate with the same power supplies.

The nonlinearity and monotonicity of the ALD1801 applies
over the full rated operating temperature. The device has
been developed with minimal temperature drift, typically
at ±10ppm/°C. A single array of matched and tracked
resistor networks of nominal 50KΩ can be used for all the
resistors required for the D/A converter. As an example,

can be set to 25KΩ by connecting two 50KΩ resistors

R

REF

in parallel where output resistors are set at 50KΩ.
Due to the very low quiescent and reference currents

used, layout of the circuit board to minimize any parasitic
capacitance is important in getting high frequency
operation, as the settling time is due in large part to the
output currents charging and discharging the node
capacitances at the output. As the internal bias current
levels is adaptive to the reference current, the switching
speed of the device depends on the reference current
selected. Characterization of the settling time has been
performed at full scale current set at 100µA and device
operation at single 5V supply. Faster operation can be
obtained by using short leads, minimizing output
capacitance, load resistor values, and by adequate bypass
capacitors placed on the board at the supply and reference
nodes.

and Io outputs can be used simultaneously. If one

Both I

o

of the outputs is not used, then it must be connected to
ground or a potential where the sum of I

and Io can

o

maintain a constant value. Due to internal leakage currents
that vary with temperature, it is recommended that I

FS

of
50µA to 100µA be used so that 1/2LSB bit current is set at
as high a level as possible. The temperature coefficient
of the reference resistor R
and R

should match to minimize temperature drift.

OUT

and output resistors R

REF

OUT

ALD1801A/ALD1801B Advanced Linear Devices 5
ALD1801

TYPICAL PERFORMANCE CHARACTERISTICS

PROPAGATION DELAY (µsec)

PROPAGATION DELAY AS A FUNCTION

OF FULL SCALE OUTPUT CURRENT

1.9

1.7

1.5

1.3

1.1
20 40 60 80 100

OUTPUT CURRENT (µA)

SUPPLY CURRENT AS A FUNCTION

OF SUPPLY VOLTAGE

FULL SCALE

800


T

= 25°C

A

SUPPLY CURRENT AS A FUNCTION

OF TEMPERATURE

I

800


600

400

200

SUPPLY CURRENT (µA)

0

1200

S-

VS = ±2.5V

I

S+

VS = ±2.5V

I

S-

VS = ±1.65V

I

S+

VS = ±1.65V

0 255075100

TEMPERATURE (°C)

ALL BITS "HIGH "
V

= V+

REF

R

= 25K

REF

125-25

FULL SCALE OUTPUT CURRENT

AS A FUNCTION OF SUPPLY VOLTAGE

100

80

I

REF

= 100µA

600

400

200

SUPPLY CURRENT (µA)

0

150

100

50

OUTPUT CURRENT (µA)

I

= 100µA

REF

I

= 0

REF

±1 ±2 ±3 ±4 ±5

SUPPLY VOLTAGE (V)

FULL SCALE OUTPUT CURRENT

AS A FUNCTION OF OUTPUT

VOLTAGE (COMPLIANCE)

VS = ±2.5V

VS = ±1.65V

V

= ±1.65V

VS = ±2.5V

S

I

REF

I

REF

= 100µA

= 50µA

60

I

40

20

0

±60

FULL SCALE OUTPUT CURRENT (µA)

0 ±1 ±2

SUPPLY VOLTAGE (V)

±3

= 50µA

REF

±4 ±5 ±6

FULL SCALE OUTPUT CURRENT

AS A FUNCTION

OF REFRENCE CURRENT

150

VS = ±1.65V TO ±2.5V

125

100

75

50

OUTPUT CURRENT (µA)

25

0

-2 -1

SUPPLY VOLTAGE (V)

+1 +2

0

0

25 50 75 100 125

REFRENCE CURRENT (µA)

1500

ALD1801A/ALD1801B Advanced Linear Devices 6
ALD1801