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MAX525 Datasheet

Download or read online Maxim Integrated MAX525 Low-Power / Quad / 12-Bit Voltage-Output DAC with Serial Interface pdf datasheet.



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19-1098; Rev 1; 12/96
Low-Power, Quad, 12-Bit Voltage-Output DAC
__________________General Description
The MAX525 combines four low-power, voltage-output,
12-bit digital-to-analog converters (DACs) and four pre-
cision output amplifiers in a space-saving, 20-pin pack-
age. In addition to the four voltage outputs, each
amplifier’s negative input is also available to the user.
This facilitates specific gain configurations, remote
sensing, and high output drive capacity, making the
MAX525 ideal for industrial-process-control applica-
tions. Other features include software shutdown, hard-
ware shutdown lockout, an active-low reset which clears
all registers and DACs to zero, a user-programmable
logic output, and a serial-data output.
Each DAC has a double-buffered input organized as an
input register followed by a DAC register. A 16-bit serial
word loads data into each input/DAC register. The serial
interface is compatible with SPI™/QSPI™ and
Microwire™. It allows the input and DAC registers to be
updated independently or simultaneously with a single
software command. The DAC registers can be simulta-
neously updated via the 3-wire serial interface. All logic
inputs are TTL/CMOS-logic compatible.
________________________Applications
Industrial Process Controls
Automatic Test Equipment
Digital Offset and Gain Adjustment
Motion Control
Remote Industrial Controls
Microprocessor-Controlled Systems
_________________________________________________________________________Functional Diagram
DOUT
CL
PDL
DECODE
CONTROL
16-BIT
SHIFT
REGISTER
SR
LOGIC
CONTROL
OUTPUT
CS DIN SCLK
UPO
SPI and QSPI are trademarks of Motorola, Inc. Microwire is a trademark of National Semiconductor Corp.
________________________________________________________________ Maxim Integrated Products
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 408-737-7600 ext. 3468.
with Serial Interface
______________________________Features
Four 12-Bit DACs with Configurable
Output Amplifiers
+5V Single-Supply Operation
Low Supply Current: 0.85mA Normal Operation
Available in 20-Pin SSOP
Power-On Reset Clears all Registers and
DACs to Zero
Capable of Recalling Last State Prior to Shutdown
SPI/QSPI and Microwire Compatible
Simultaneous or Independent Control of DACs
via 3-Wire Serial Interface
User-Programmable Digital Output
_________________Ordering Information
PART
MAX525ACPP
MAX525BCPP
MAX525ACAP
MAX525BCAP
Ordering Information continued on last page.
Pin Configuration appears at end of data sheet.
V
REFAB
DGND
AGND
DD
MAX525
INPUT
DAC
DAC A
REGISTER A
REGISTER A
INPUT
DAC
DAC B
REGISTER B
REGISTER B
INPUT
DAC
DAC C
REGISTER C
REGISTER C
INPUT
DAC
DAC D
REGISTER D
REGISTER D
REFCD
10µA Shutdown Mode
INL
TEMP. RANGE
PIN-PACKAGE
(LSB)
0°C to +70°C
20 Plastic DIP
±1/2
0°C to +70°C
20 Plastic DIP
±1
0°C to +70°C
20 SSOP
±1/2
0°C to +70°C
20 SSOP
±1
FBA
OUTA
FBB
OUTB
FBC
OUTC
FBD
OUTD
1

Summary of Contents

Page 1

... Rev 1; 12/96 Low-Power, Quad, 12-Bit Voltage-Output DAC ___General Description The MAX525 combines four low-power, voltage-output, 12-bit digital-to-analog converters (DACs) and four pre- cision output amplifiers in a space-saving, 20-pin pack- age. In addition to the four voltage outputs, each amplifiers negative input is also available to the user. ...

Page 2

... REFERENCE INPUT Reference Input Range V REF Reference Input Resistance R REF Reference Current in Shutdown 2 ___ Operating Temperature Ranges MAX525_C_P ...0°C to 70°C MAX525_E_P ...-40°C to 85°C 0.3V) MAX525_MJP ...-55°C to 125° 0.3V) Storage Temperature Range ...-65°C to 150°C DD Lead Temperature (soldering, 10sec) ...300°C 0.3V 5kΩ ...

Page 3

Low-Power, Quad, 12-Bit Voltage-Output DAC ELECTRICAL CHARACTERISTICS (continued 5V ±10%, AGND DGND 0V, REFAB REFCD 2.5V noted. Typical values are 25°C. Output buffer connected in unity-gain configuration (Figure 9).) ...

Page 4

Low-Power, Quad, 12-Bit Voltage-Output DAC with Serial Interface ELECTRICAL CHARACTERISTICS (continued 5V ±10%, AGND DGND 0V, REFAB REFCD 2.5V noted. Typical values are 25°C. Output buffer connected in unity-gain ...

Page 5

Low-Power, Quad, 12-Bit Voltage-Output DAC ___Typical Operating Characteristics (continued 5V 25°C, unless otherwise noted SUPPLY CURRENT vs. SUPPLY VOLTAGE 1000 950 900 850 800 750 700 650 CODE FFF hex 600 4.0 4.2 ...

Page 6

Low-Power, Quad, 12-Bit Voltage-Output DAC with Serial Interface ___Typical Operating Characteristics (continued 5V 25°C, unless otherwise noted MAJOR-CARRY TRANSITION 10 s/div V 2.5V 100pF REF L L ...

Page 7

Low-Power, Quad, 12-Bit Voltage-Output DAC ___Pin Description PIN NAME 1 AGND Analog Ground 2 FBA DAC A Output Amplifier Feedback 3 OUTA DAC A Output Voltage 4 OUTB DAC B Output Voltage 5 FBB DAC B Output Amplifier Feedback 6 ...

Page 8

... The power-down lockout (PDL) pin must be high to DD enable the shutdown mode. Writing 1100XXXXXXXXXXXX are represented by as the input-control word puts the MAX525 in power- down mode (Table 1). Output Amplifiers Power-Down Mode ...

Page 9

... How the part is configured when coming out of shut- down mode. ___ with Serial Interface SCLK DIN MAX525 DOUT CS THE DOUT-SI CONNECTION IS NOT REQUIRED FOR WRITING TO THE MAX525, BUT MAY BE USED FOR READBACK PURPOSES. Figure 2. Connections for Microwire DOUT DIN MAX525 SCLK CS CPOL 0, CPHA 0 THE DOUT-MISO CONNECTION IS NOT REQUIRED FOR WRITING TO THE MAX525, BUT MAY BE USED FOR READBACK PURPOSES ...

Page 10

... Register allows all input and DAC registers to be simul- taneously loaded with the same digital code from the input shift register. The no operation (NOP) command leaves the register contents unaffected and is useful when the MAX525 is configured in a daisy chain (see the Daisy Chaining Devices section). The command to 10 ___ ...

Page 11

... PDL from high to low wakes up the part with the output set to the state prior to shutdown. PDL could also be used to asynchronously wake up the device. Daisy Chaining Devices Any number of MAX525s can be daisy chained by con- necting the DOUT pin of one device to the DIN pin of the following device in the chain (Figure 7). ___ ...

Page 12

... Serial Interface MAX525 SCLK SCLK DIN DOUT DIN CS CS Figure 7. Daisy-Chaining MAX525s DIN SCLK CS1 CS2 CS3 CS MAX525 SCLK DIN Figure 8. Multiple MAX525s Sharing a Common DIN Line 12 ___ MAX525 MAX525 SCLK SCLK DOUT DOUT DIN DIN MAX525 SCLK SCLK DIN ...

Page 13

... Information For a unipolar output, the output voltages and the refer- ence inputs have the same polarity. Figure 9 shows the MAX525 unipolar output circuit, which is also the typi- cal operating circuit. Table 2 lists the unipolar output codes. For rail-to-rail outputs, see Figure 10. This circuit shows ...

Page 14

... REFAB/REFCD. The reference voltage OUTA must never be more negative than DGND. 10k FBB The MAX525s total harmonic distortion plus noise (THD 10k N) is typically less than -72dB, given a 1Vp-p signal swing and input frequencies up to 25kHz. The typical OUTB ...

Page 15

... Power-Supply Considerations On power-up, all input and DAC registers are cleared (set to zero code) and DOUT is in Mode 0 (serial data is shifted out of DOUT on the clocks falling edge). For rated MAX525 performance, limit REFAB/REFCD to less than 1.4V below V . Bypass V DD capacitor in parallel with a 0.1µF capacitor to AGND. ...

Page 16

... Dice MAX525AEPP -40°C to 85°C 20 Plastic DIP MAX525BEPP -40°C to 85°C 20 Plastic DIP MAX525AEAP -40°C to 85°C 20 SSOP MAX525BEAP -40°C to 85°C 20 SSOP MAX525AMJP -55°C to 125°C 20 CERDIP MAX525BMJP -55°C to 125°C 20 CERDIP Dice are specified 25°C, DC parameters only. A Contact factory for availability and processing to MIL-STD-883. ...

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