ANALOG DEVICES AD5620, AD5640, AD5660 Service Manual

FEATURES

Low power, single nanoDACs AD5660: 16 bits

AD5640: 14 bits AD5620: 12 bits

12-bit accuracy guaranteed

On-chip, 1.25 V/2.5 V, 5 ppm/°C reference Tiny 8-lead SOT-23/MSOP packages Power-down to 480 nA @ 5 V, 200 nA @ 3 V 3 V/5 V single power supply

Guaranteed 16-bit monotonic by design Power-on reset to zero/midscale

3 power-down functions

Serial interface with Schmitt-triggered inputs Rail-to-rail operation

SYNC interrupt facility

Single, 12-/14-/16-Bit nanoDAC with 5 ppm/°C On-Chip Reference in SOT-23 AD5620/AD5640/AD5660

FUNCTIONAL BLOCK DIAGRAM

	VREFOUT	GND	VDD
POWER-ON	1.25/2.5V		AD5620/AD5640/AD5660
		REF
RESET					VFB
DAC	REF(+)			OUTPUT	VOUT
	16-BIT			BUFFER
REGISTER
	DAC
INPUT		POWER-DOWN
CONTROL				RESISTOR
	CONTROL LOGIC
LOGIC				NETWORK
					04539-001

SYNC SCLK DIN

Figure 1.

APPLICATIONS

Process control

Data acquisition systems

Portable battery-powered instruments

Digital gain and offset adjustment

Programmable voltage and current sources

Programmable attenuators

PRODUCT HIGHLIGHTS

1.12-/14-/16-bit nanoDAC—12-bit accuracy guaranteed.

2.On-chip, 1.25 V/2.5 V, 5 ppm/°C reference.

3.Available in 8-lead SOT-23 and 8-lead MSOP packages.

4.Power-on reset to 0 V or midscale.

5.10 μs settling time.

Table 1. Related Device

Part No.	Description
AD5662	2.7 V to 5.5 V, 16-bit DAC in SOT-23, external
	reference

GENERAL DESCRIPTION

The AD5620/AD5640/AD5660, members of the nanoDAC™ family of devices, are low power, single, 12-/14-/16-bit, buffered voltage-out DACs and are guaranteed monotonic by design.

The AD5620/AD5640/AD5660-1 parts include an internal, 1.25 V, 5 ppm/°C reference, giving a full-scale output voltage range of 2.5 V. The AD5620/AD5640/AD5660-2-3 parts include an internal, 2.5 V, 5 ppm/°C reference, giving a full-scale output voltage range of 5 V. The reference associated with each part is available at the VREFOUT pin.

The parts incorporate a power-on reset circuit to ensure that the DAC output powers up to 0 V (AD5620/AD5640/AD5660-1-2) or midscale (AD5620-3 and AD5660-3) and remains there until a valid write takes place. The parts contain a power-down feature that reduces the current consumption of the device to 480 nA at 5 V and provides software-selectable output loads while in power-down mode. The power consumption is

2.5 mW at 5 V, reducing to 1 μW in power-down mode.

The AD5620/AD5640/AD5660 on-chip precision output amplifier allows rail-to-rail output swing to be achieved. For remote sensing applications, the output amplifier’s inverting input is available to the user. The AD5620/AD5640/AD5660 use a versatile 3-wire serial interface that operates at clock rates up to 30 MHz and is compatible with standard SPI®, QSPI™, MICROWIRE™, and DSP interface standards.

Rev. F

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibilityisassumedbyAnalogDevicesforitsuse,norforanyinfringementsofpatentsorother rightsofthirdpartiesthatmayresultfromitsuse.Specificationssubjecttochangewithoutnotice.No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarksandregisteredtrademarksarethepropertyoftheirrespectiveowners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: [phone] www.analog.com Fax: [phone] ©2005–2010 Analog Devices, Inc. All rights reserved.

AD5620/AD5640/AD5660

TABLE OF CONTENTS
Features ..............................................................................................	1
Applications.......................................................................................	1
Product Highlights ...........................................................................	1
Functional Block Diagram ..............................................................	1
General Description .........................................................................	1
Revision History ...............................................................................	2
Specifications.....................................................................................	3
AD5620/AD5640/AD5660-2-3 ..................................................	3
AD5620/AD5640/AD5660-1......................................................	5
Timing Characteristics ................................................................	7
Absolute Maximum Ratings............................................................	8
ESD Caution..................................................................................	8
Pin Configurations and Function Descriptions ...........................	9
Typical Performance Characteristics ...........................................	10
Terminology ....................................................................................	16
Theory of Operation ......................................................................	17
D/A Section.................................................................................	17
Resistor String.............................................................................	17
REVISION HISTORY
12/10—Rev. E to Rev. F
Changes to Ordering Guide ..........................................................	25
7/10—Rev. D to Rev. E
Moved Using the AD5660 as an Isolated, Programmable, 4 mA
to 20 mA Process Controller Section...........................................	22
Moved Power Supply Bypassing and Grounding Section.........	23
Changes to Ordering Guide ..........................................................	25
3/10—Rev. C to Rev. D
Changes to Ordering Guide ..........................................................	24
10/09—Rev. B to Rev. C
Changes to Ordering Guide ..........................................................	23

Internal Reference ......................................................................	17
Output Amplifier........................................................................	17
Serial Interface ............................................................................	17
Input Shift Register ....................................................................	18
SYNC Interrupt ..........................................................................	18
Power-On Reset..........................................................................	19
Power-Down Modes ..................................................................	19
Microprocessor Interfacing.......................................................	19
Applications Information ..............................................................	21
Using a REF19x as a Power Supply for the
AD5620/AD5640/AD5660 .......................................................	21
Bipolar Operation Using the AD5660 .....................................	21
Using the AD5660 as an Isolated, Programmable, 4 mA to
20 mA Process Controller .........................................................	22
Using the AD5620/AD5640/AD5660 with a Galvanically
Isolated Interface ........................................................................	22
Power Supply Bypassing and Grounding................................	23
Outline Dimensions .......................................................................	24
Ordering Guide ..........................................................................	25

5/06—Rev. A to Rev. B
Updated Formatted ............................................................	Universal
Updated Temperature Range ............................................	Universal
Changes to Table 2.............................................................................	3
Changes to Table 5.............................................................................	8
Replaced Figure 17, Figure 18, and Figure 19.............................	12
Changes to Ordering Guides ..................................................	23, 24
9/05—Rev. 0 to Rev. A
Changes to Specifications.................................................................	5
Changes to Outline Dimensions ..................................................	23
7/05—Revision 0: Initial Version

Rev. F | Page 2 of 28

AD5620/AD5640/AD5660

SPECIFICATIONS

AD5620/AD5640/AD5660-2-3

VDD = 4.5 V to 5.5 V, RL = 2 kΩ to GND, CL = 200 pF to GND, CREFOUT = 100 nF; all specifications TMIN to TMAX, unless otherwise noted.

Table 2.

Parameter	A Grade1	B Grade1	C Grade1	Unit	Conditions/Comments
STATIC PERFORMANCE2
AD5660
Resolution	16	16	16	Bits min
Relative Accuracy	±32	±16	±16	LSB max
Differential Nonlinearity	±1	±1	±1	LSB max	Guaranteed monotonic by design
AD5640
Resolution	14	14	14	Bits min
Relative Accuracy	±8	±4	±4	LSB max
Differential Nonlinearity	±0.5	±0.5	±0.5	LSB max	Guaranteed monotonic by design
AD5620
Resolution	12	12	12	Bits min
Relative Accuracy	±6	±1	±1	LSB max
Differential Nonlinearity	±0.25	±0.25	±0.25	LSB max	Guaranteed monotonic by design
Zero-Code Error	2	2	2	mV typ	All 0s loaded to DAC register
	10	10	10	mV max
Offset Error	±10	±10	±10	mV max
Full-Scale Error	−0.15	−0.15	−0.15	% FSR typ	All 1s loaded to DAC register
	±1	±1	±1	% FSR max
Gain Error	±1.5	±1.5	±1.5	% FSR max
Zero-Code Error Drift	±2	±2	±2	μV/°C typ
Gain Temperature Coefficient	±2.5	±2.5	±2.5	ppm typ	Of FSR/°C
DC Power Supply Rejection Ratio	−75	−75	−75	dB typ	DAC code = midscale; VDD = 5 V ± 10%
OUTPUT CHARACTERISTICS3
Output Voltage Range	0	0	0	V min
	VDD	VDD	VDD	V max
Output Voltage Settling Time	8	8	8	μs typ	¼ to ¾ scale change settling to ±2 LSB
	10	10	10	μs max	RL = 2 kΩ; 0 pF < CL < 200 pF
Slew Rate	1.5	1.5	1.5	V/μs typ	¼ to ¾ scale
Capacitive Load Stability	2	2	2	nF typ	RL = ∞
	10	10	10	nF typ	RL = 2 kΩ
Output Noise Spectral Density	80	80	80	nV/√Hz typ	DAC code = midscale, 10 kHz
Output Noise (0.1 Hz to 10 Hz)	45	45	45	μV p-p typ	DAC code = midscale
Digital-to-Analog Glitch Impulse	5	5	5	nV-s typ	1 LSB change around major carry
Digital Feedthrough	0.1	0.1	0.1	nV-s typ
DC Output Impedance	0.5	0.5	0.5	Ω typ
Short-Circuit Current	30	30	30	mA typ	VDD = 5 V
Power-Up Time	5	5	5	μs typ	Coming out of power-down mode; VDD = 5 V
REFERENCE OUTPUT
Output Voltage	2.495	2.495	2.495	V min	At ambient
	2.505	2.505	2.505	V max
Reference TC3	±10	±10	±5	ppm/°C typ
			±10	ppm/°C max
Output Impedance	7.5	7.5	7.5	kΩ typ

Rev. F | Page 3 of 28

AD5620/AD5640/AD5660

Parameter	A Grade1	B Grade1	C Grade1	Unit	Conditions/Comments
LOGIC INPUTS3
Input Current	±2	±2	±2	μA max	All digital inputs
VINL, Input Low Voltage	0.8	0.8	0.8	V max	VDD = 5 V
VINH, Input High Voltage	2	2	2	V min	VDD = 5 V
Pin Capacitance	3	3	3	pF typ
POWER REQUIREMENTS
VDD	4.5	4.5	4.5	V min	All digital inputs at 0 V or VDD
	5.5	5.5	5.5	V max	DAC active and excluding load current
IDD (Normal Mode)
VDD = 4.5 V to 5.5 V	0.55	0.55	0.55	mA typ	VIH = VDD and VIL = GND
VDD = 4.5 V to 5.5 V	1	1	1	mA max	VIH = VDD and VIL = GND
IDD (All Power-Down Modes)
VDD = 4.5 V to 5.5 V	0.48	0.48	0.48	μA typ	VIH = VDD and VIL = GND
VDD = 4.5 V to 5.5 V	1	1	1	μA max	VIH = VDD and VIL = GND

1 Temperature range is −40°C to +105°C, typical at +25°C.

2Linearity calculated using a reduced code range: AD5660 (Code 511 to Code 65024); AD5640 (Code 128 to Code 16256); AD5620 (Code 32 to Code 4064). Output unloaded. Linearity tested with VDD = 5.5 V. If part is operated with a VDD < 5 V, the output is clamped to VDD.

3 Guaranteed by design and characterization; not production tested.

Rev. F | Page 4 of 28

AD5620/AD5640/AD5660

AD5620/AD5640/AD5660-1

VDD1 = 2.7 V to 3.3 V, RL = 2 kΩ to GND, CL = 200 pF to GND, CREFOUT = 100 nF; all specifications TMIN to TMAX, unless otherwise noted.

Table 3.

Parameter	A Grade2	B Grade2	C Grade2	Unit	Conditions/Comments
STATIC PERFORMANCE3
AD5660
Resolution	16	16	16	Bits min
Relative Accuracy	±32	±16	±16	LSB max
Differential Nonlinearity	±1	±1	±1	LSB max	Guaranteed monotonic by design
AD5640
Resolution	14	14	14	Bits min
Relative Accuracy	±8	±4	±4	LSB max
Differential Nonlinearity	±0.5	±0.5	±0.5	LSB max	Guaranteed monotonic by design
AD5620
Resolution	12	12	12	Bits min
Relative Accuracy	±6	±1	±1	LSB max
Differential Nonlinearity	±0.25	±0.25	±0.25	LSB max	Guaranteed monotonic by design
Zero-Code Error	2	2	2	mV typ	All 0s loaded to DAC register
	8	8	8	mV max
Offset Error	±9	±9	±9	mV max
Full-Scale Error	±0.15	±0.15	±0.15	% FSR typ	All 1s loaded to DAC register
	±0.85	±0.85	±0.85	% FSR max
Gain Error	±0.85	±0.85	±0.85	% FSR max
Zero-Code Error Drift	±2	±2	±2	μV/°C typ
Gain Temperature Coefficient	±2.5	±2.5	±2.5	ppm typ	Of FSR/°C
DC Power Supply Rejection Ratio	−60	−60	−60	dB typ	DAC code = midscale; VDD = 3 V ± 10%
OUTPUT CHARACTERISTICS4
Output Voltage Range	0	0		V min
	VDD	VDD	VDD	V max
Output Voltage Settling Time	8	8	8	μs typ	¼ to ¾ scale change settling to ±2 LSB
	10	10	10	μs max	RL = 2 kΩ; 0 pF < CL < 200 pF
Slew Rate	1.5	1.5	1.5	V/μs typ	¼ to ¾ scale
Capacitive Load Stability	2	2	2	nF typ	RL = ∞
	10	10	10	nF typ	RL = 2 kΩ
Output Noise Spectral Density	80	80	80	nV/√Hz typ	DAC code = midscale, 10 kHz
Output Noise (0.1 Hz to 10 Hz)	20	20	20	μV p-p typ	DAC code = midscale
Digital-to-Analog Glitch Impulse	5	5	5	nV-s typ	1 LSB change around major carry
Digital Feedthrough	0.1	0.1	0.1	nV-s typ
DC Output Impedance	0.5	0.5	0.5	Ω typ
Short-Circuit Current	30	30	30	mA typ	VDD = 3 V
Power-Up Time	6	6	6	μs typ	Coming out of power-down mode; VDD = 3 V
REFERENCE OUTPUT
Output Voltage	1.247	1.247	1.247	V min	At ambient
	1.253	1.253	1.253	V max
Reference TC4	±10	±10	±5	ppm/°C typ
			±15	ppm/°C max
Output Impedance	7.5	7.5	7.5	kΩ typ

Rev. F | Page 5 of 28

AD5620/AD5640/AD5660

Parameter	A Grade2	B Grade2	C Grade2	Unit	Conditions/Comments
LOGIC INPUTS4
Input Current	±1	±1	±1	μA max	All digital inputs
VINL, Input Low Voltage	0.8	0.8	0.8	V max	VDD = 3 V
VINH, Input High Voltage	2	2	2	V min	VDD = 3 V
Pin Capacitance	3	3	3	pF max
POWER REQUIREMENTS
VDD	2.7	2.7	2.7	V min	All digital inputs at 0 V or VDD
	3.3	3.3	3.3	V max	DAC active and excluding load current
IDD (Normal Mode)
VDD = 2.7 V to 3.3 V	0.55	0.55	0.55	mA typ	VIH = VDD and VIL = GND
VDD = 2.7 V to 3.3 V	0.65	0.65	0.65	mA max	VIH = VDD and VIL = GND
IDD (All Power-Down Modes)
VDD = 2.7 V to 3.3 V	0.2	0.2	0.2	μA typ	VIH = VDD and VIL = GND
VDD = 2.7 V to 3.3 V	0.25	0.25	0.25	μA max	VIH = VDD and VIL = GND

1 Part is functional with VDD up to 5.5 V.

2 Temperature range is −40°C to +105°C, typical at +25°C.

3 Linearity calculated using a reduced code range: AD5660 (Code 511 to Code 65024); AD5640 (Code 128 to Code 16256); AD5620 (Code 32 to Code 4064). Output unloaded.

4 Guaranteed by design and characterization; not production tested.

Rev. F | Page 6 of 28

AD5620/AD5640/AD5660

TIMING CHARACTERISTICS

All input signals are specified with tr = tf = 1 ns/V (10% to 90% of VDD) and timed from a voltage level of (VIL + VIH)/2. See Figure 2. VDD = 2.7 V to 5.5 V; all specifications TMIN to TMAX, unless otherwise noted.

Table 4.

	Limit at TMIN, TMAX
Parameter	VDD = 2.7 V to 3.6 V	VDD = 3.6 V to 5.5 V	Unit		Conditions/Comments
t11	50	33	ns min		SCLK cycle time
t2	13	13	ns min		SCLK high time
t3	13	13	ns min		SCLK low time
t4	13	13	ns min
					SYNC	to SCLK falling edge setup time
t5	5	5	ns min		Data setup time
t6	4.5	4.5	ns min		Data hold time
t7	0	0	ns min
					SCLK falling edge to				SYNC	rising edge
t8	50	33	ns min
					Minimum		SYNC	high time
t9	13	13	ns min
					SYNC	rising edge to SCLK fall ignore
t10	0	0	ns min
					SCLK falling edge to				SYNC	fall ignore

1 Maximum SCLK frequency is 30 MHz at VDD = 3.6 V to 5.5 V and 20 MHz at VDD = 2.7 V to 3.6 V.

		t10		t1		t9
SCLK
	t8	t4	t3		t2	t7
SYNC
			t6
			t5
DIN		MSB				LSB

LSB = DB0

MSB = DB23 FOR AD5660

MSB = DB15 FOR AD5620/AD5640

Figure 2. Serial Write Operation

04539-002

Rev. F | Page 7 of 28

AD5620/AD5640/AD5660

ABSOLUTE MAXIMUM RATINGS

TA = 25°C, unless otherwise noted.

Table 5.

Parameter	Rating
VDD to GND	−0.3 V to +7 V
VOUT to GND	−0.3 V to VDD + 0.3 V
VFB to GND	−0.3 V to VDD + 0.3 V
VREFOUT to GND	−0.3 V to VDD + 0.3 V
Digital Input Voltage to GND	−0.3 V to VDD + 0.3 V
Operating Temperature Range
Industrial	−40°C to +105°C
Storage Temperature Range	−65°C to +150°C
Junction Temperature (TJ max)	150°C
Power Dissipation	(TJ max − TA)/θJA
SOT-23 Package (4-Layer Board)
θJA Thermal Impedance	119°C/W
MSOP Package (4-Layer Board)
θJA Thermal Impedance	141°C/W
θJC Thermal Impedance	44°C/W
Reflow Soldering Peak Temperature
SnPb	240°C
Pb-Free	260°C

Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

ESD CAUTION

Rev. F | Page 8 of 28

PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS

VDD	1	AD5620/	8	GND
V	2	AD5640/	7	DIN
REFOUT		AD5660
VFB	3		6	SCLK
		TOP VIEW					003-04539
VOUT	4	(Not to Scale)	5
					SYNC

Figure 3. SOT-23 Pin Configuration

AD5620/AD5640/AD5660

VDD	1	AD5620/	8	GND
VREFOUT	2	AD5640/	7	DIN
VFB	3	AD5660	6	SCLK			-04539004
		TOP VIEW
VOUT	4	(Not to Scale)	5	SYNC

Figure 4. MSOP Pin Configuration

Table 6. Pin Function Descriptions

Pin No. Mnemonic

1VDD

2VREFOUT

3VFB

4VOUT

5SYNC

6SCLK

7DIN

8GND

Description

Power Supply Input. These parts can operate from 2.7 V to 5.5 V. VDD should be decoupled to GND. Reference Voltage Output.

Feedback Connection for the Output Amplifier. VFB should be connected to VOUT for normal operation. Analog Output Voltage from DAC. The output amplifier has rail-to-rail operation.

Level-Triggered Control Input (Active Low). This is the frame synchronization signal for the input data. When SYNC goes low, it enables the input shift register and data is transferred in on the falling edges of the following clocks. The DAC is updated following the 24th clock cycle for the AD5660 and the 16th clock cycle for AD5620/AD5640 unless SYNC is taken high before this edge. In this case, the rising edge of SYNC acts as an interrupt, and the write sequence is ignored by the DAC.

Serial Clock Input. Data is clocked into the input shift register on the falling edge of the serial clock input. Data can be transferred at rates up to 30 MHz.

Serial Data Input. The AD5660 has a 24-bit shift register, and the AD5620/AD5640 have a 16-bit shift register. Data is clocked into the register on the falling edge of the serial clock input.

Ground Reference Point for all Circuitry on the Part.

Rev. F | Page 9 of 28