AD7524M Advanced LinCMOS 8-BIT MULTIPLYING DIGITAL-TO-ANALOG CONVERTER SGLS028A – SEPTEMBER 1989 – REVISED MARCH 1995 D D D D D D Advanced LinCMOS Silicon-Gate Technology Easily interfaced to Microprocessors On-Chip Data Latches Monotonicity Over Entire A/D Conversion Range Segmented High-Order Bits Ensure Low-Glitch Output Designed to Be interchangeable With Analog Devices AD7524, PMI PM-7524, and Micro Power Systems MP7524 Fast Control Signaling for Digital Signal Processor Applications Including Interface With SMJ320 J PACKAGE (TOP VIEW) OUT1 OUT2 GND DB7 DB6 DB5 DB4 DB3 1 16 2 15 3 14 4 13 5 12 6 11 7 10 8 9 RFB REF VDD WR CS DB0 DB1 DB2 FK PACKAGE (TOP VIEW) OUT2 OUT1 NC RFB REF D KEY PERFORMANCE SPECIFICATIONS Resolution 8 Bits Linearity error 1/2 LSB Max Power dissipation at VDD = 5 V 5 mW Max Settling time 100 ns Max Propagation delay 80 ns Max GND DB7 NC DB6 DB5 3 2 1 20 19 18 5 17 6 16 7 15 8 14 9 10 11 12 13 VDD WR NC CS DB0 DB4 DB3 NC DB2 DB1 description 4 The AD7524M is an Advanced LinCMOS 8-bit digital-to-analog converter (DAC) designed for easy interface to most popular microprocessors. NC–No internal connection The AD7524M is an 8-bit multiplying DAC with input latches and with a load cycle similar to the write cycle of a random access memory. Segmenting the high-order bits minimizes glitches during changes in the most-significant bits, which produce the highest glitch impulse. The AD7524M provides accuracy to 1/2 LSB without the need for thin-film resistors or laser trimming, while dissipating less than 5 mW typically. Featuring operation from a 5-V to 15-V single supply, the AD7524M interfaces easily to most microprocessor buses or output ports. Excellent multiplying (2 or 4 quadrant) makes the AD7524M an ideal choice for many microprocessor-controlled gain-setting and signal-control applications. The AD7524M is characterized for operation from – 55°C to 125°C. AVAILABLE OPTIONS PACKAGE TA CERAMIC CHIP CARRIER (FK) – 55°C to 125°C AD7524MFK CERAMIC DIP (J) AD7524MJ Advanced LinCMOS is a trademark of Texas Instruments Incorporated. Copyright 1995, 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. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1 AD7524M Advanced LinCMOS 8-BIT MULTIPLYING DIGITAL-TO-ANALOG CONVERTER SGLS028A – SEPTEMBER 1989 – REVISED MARCH 1995 functional block diagram R 15 R R REF 2R 2R 2R 2R 2R 16 S-1 S-2 S-3 S-8 R 1 2 CS WR RFB OUT1 OUT2 12 3 Data Latches 13 4 DB7 (MSB) 5 DB6 6 11 DB5 DB0 (LSB) GND Data Inputs operating sequence ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ tsu(CS) CS 10% th(CS) tw(WR) WR 10% 10% tsu(D) DB0 – DB7 2 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 th(D) AD7524M Advanced LinCMOS 8-BIT MULTIPLYING DIGITAL-TO-ANALOG CONVERTER SGLS028A – SEPTEMBER 1989 – REVISED MARCH 1995 absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† Supply voltage range, VDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.3 V to 17 V Voltage between RFB and GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 25 V Digital input voltage range, VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.3 V to VDD+0.3 V Reference voltage range, Vref . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 25 V Peak digital input current, II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 µA Operating free-air temperature range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 55°C to 125°C Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 65°C to 150°C Case temperature for 60 seconds, TC: FK package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C Lead temperature 1,6 mm (1/16 inch) from case for 60 seconds: J package . . . . . . . . . . . . . . . . . . . . . 300°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. recommended operating conditions Supply voltage, VDD VDD = 5 V MIN NOM MAX VDD = 15 V MIN NOM MAX 4.75 14.5 5 5.25 ± 10 Reference voltage, Vref High-level input voltage, VIH V V 13.5 0.8 CS setup time, tsu(CS) 15.5 ± 10 2.4 Low-level input volage, VIL 15 UNIT V 1.5 V 40 40 ns 0 0 ns Data bus input setup time, tsu(D) 25 25 ns Data bus input hold time, th(D) 10 10 ns Pulse duration, WR low, tw(WR) 40 40 ns CS hold time, th(CS) Operating free-air temperature, TA – 55 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 125 – 55 125 °C 3 AD7524M Advanced LinCMOS 8-BIT MULTIPLYING DIGITAL-TO-ANALOG CONVERTER SGLS028A – SEPTEMBER 1989 – REVISED MARCH 1995 electrical characteristics over recommended operating free-air temperature range, Vref = 10 V, OUT1 and OUT2 at GND (unless otherwise noted) PARAMETER IIH High level input current High-level VI = VDD IIL Low level input current Low-level VI = 0 Ipkg k IDD MIN 10 10 25°C 1 1 Full-range – 10 – 10 25°C –1 –1 Full-range ± 400 ± 200 25°C ± 50 ± 50 Full-range ± 400 ± 200 ± 50 ± 50 DB0–DB7 at 0, WR and CS at 0 V OUT2 Vref = ±10 V DB0–DB7 at VDD, WR and CS at 0 Quiescent Vref = ±10 V 25°C DB0–DB7 at VIHmin or VILmax Standby DB0 DB7 at 0 V or VDD DB0–DB7 kSVS Supplyy voltage g sensitivity, y, ∆gain/∆VDD ∆VDD = 10% Ci Input capacitance, DB0–DB7, WR, CS VI = 0 Co Output capacitance 2 2 Full-range 500 500 25°C 100 100 Full-range 0.16 25°C 0.002 DB0 DB7 at 0, DB0–DB7 0 WR and CS at 0 V OUT1 OUT2 0.02 0.001 5 OUT1 OUT2 VDD = 15 V TYP MAX MIN Full-range OUT1 Output leakage g current Supply current VDD = 5 V TYP MAX TEST CONDITIONS DB0 DB7 at VDD, WR and CS at 0 V DB0–DB7 Reference input impedance (REF to GND) 5 µA nA mA µA %/% 0.02 pF 5 pF 30 30 120 120 120 30 30 5 µA 0.04 120 20 UNIT 20 pF kΩ operating characteristics over recommended operating free-air temperature range, Vref = 10 V, OUT1 and OUT2 at GND (unless otherwise noted) PARAMETER TEST CONDITIONS Linearity error Full range VCC = 5 V MIN MAX VDD = 15 V MIN MAX UNIT ± 0.2 ± 0.2 %FSR ± 1.4 ± 0.6 ±1 ± 0.5 Gain error See Note 1 Settling time (to 1/2 LSB) See Note 2 100 100 ns Propagation delay from digital input to 90% of final analog output current See Note 2 80 80 ns Feedthrough at OUT1 or OUT2 Vref = ± 10 V ((100 kHz sinewave), ), WR and CS at 0, DB0–DB7 at 0 Temperature coefficient of gain TA = 25°C to tmin or tmax 25°C Full range 0.5 0.5 25°C 0.25 0.25 ± 0.004 ± 0.001 NOTES: 1. Gain error is measured using the internal feedback resistor. Nominal Full Scale Range (FSR) = Vref – 1 LSB. 2. OUT1 load = 100 Ω, Cext = 13 pF, WR at 0 V, CS at 0 V, DB0–DB7 at 0 V to VDD or VDD to 0 V. 4 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 %FSR %FSR %FSR/ °C AD7524M Advanced LinCMOS 8-BIT MULTIPLYING DIGITAL-TO-ANALOG CONVERTER SGLS028A – SEPTEMBER 1989 – REVISED MARCH 1995 PRINCIPLES OF OPERATION The AD7524M is an 8-bit multiplying D/A converter consisting of an inverted R-2R ladder, analog switches, and data input latches. Binary weighted currents are switched between the OUT1 and OUT2 bus lines, thus maintaining a constant current in each ladder leg independent of the switch state. The high-order bits are decoded and these decoded bits, through a modification in the R-2R ladder, control three equally weighted current sources. Most applications only require the addition of an external operational amplifier and a voltage reference. The equivalent circuit for all digital inputs low is seen in Figure 1. With all digital inputs low, the entire reference current, Iref, is switched to OUT2. The current source 1/256 represents the constant current flowing through the termination resistor of the R-2R ladder, while the current source IIkg represents leakage currents to the substrate. The capacitances appearing at OUT1 and OUT2 are dependent upon the digital input code. With all digital inputs high, the off-state switch capacitance (30 pF maximum) appears at OUT2 and the on-state switch capacitance (120 pF maximum) appears at OUT1. With all digital inputs low, the situation is reversed as shown in Figure 1. Analysis of the circuit for all digital inputs high is similar to Figure 1; however, in this case, Iref would be switched to OUT1. Interfacing the AD7524M D/A converter to a microprocessor is accomplished via the data bus and the CS and WR control signals. When CS and WR are both low, the AD7524M analog output responds to the data activity on the DB0–DB7 data bus inputs. In this mode, the input latches are transparent and input data directly affects the analog output. When either the CS signal or WR signal goes high, the data on the DB0–DB7 inputs are latched until the CS and WR signals go low again. When CS is high, the data inputs are disabled regardless of the state of the WR signal. The AD7524M is capable of performing 2-quadrant or full 4-quadrant multiplication. Circuit configurations for 2-quadrant or 4-quadrant multiplication are shown in Figures 2 and 3. Input coding for unipolar and bipolar operation are summarized in Tables 1 and 2, respectively. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5 AD7524M Advanced LinCMOS 8-BIT MULTIPLYING DIGITAL-TO-ANALOG CONVERTER SGLS028A – SEPTEMBER 1989 – REVISED MARCH 1995 PRINCIPLES OF OPERATION RFB R OUT1 I1kg 30 pF REF OUT2 1/256 120 pF I1kg Figure 1. AD7524M Equivalent Circuit With All Digital Inputs Low Vref VDD RA = 2 kΩ (see Note A) RB C (see Note B) RFB DB0 – DB7 OUT1 – Output CS + OUT2 WR GND Figure 2. Unipolar Operation (2-Quadrant Multiplication) Vref VDD 20 kΩ RA = 2 kΩ (see Note A) RB RFB DB0 – DB7 20 kΩ OUT1 CS WR – C (see Note B) OUT2 10 kΩ – + Output + 5 kΩ GND Figure 3. Bipolar Operation (4-Quadrant Operation) NOTES: A. RA and RB used only if gain adjustment is required. B. C phase compensation (10 – 15 pF) is required when using high-speed amplifiers to prevent ringing or oscillation. 6 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 AD7524M Advanced LinCMOS 8-BIT MULTIPLYING DIGITAL-TO-ANALOG CONVERTER SGLS028A – SEPTEMBER 1989 – REVISED MARCH 1995 PRINCIPLES OF OPERATION Table 1. Unipolar Binary Code DIGITAL INPUT (see NOTE 3) MSB ANALOG OUTPUT LSB 11111111 10000001 10000000 01111111 00000001 00000000 –Vref (255/256) –Vref (129/256) –Vref (128/256) = –Vref /2 –Vref (127/256) –Vref (1/256) 0 NOTES: 3. LSB = 1/256 (Vref). Table 2. Bipolar (Offset Binary) Code DIGITAL INPUT (see NOTE 4) MSB ANALOG OUTPUT LSB 11111111 10000001 10000000 01111111 00000001 00000000 Vref (127/128) Vref (128) 0 –Vref (128) –Vref (127/128) –Vref NOTES: 4. LSB = 1/128 (Vref). microprocessor interfaces Data Bus D0 – D7 Z-80A DB0 – DB7 WR WR AD7524M CS IORQ A0 – A15 OUT1 OUT2 Decode Logic Address Bus Figure 4. AD7524M – Z-80A Interface POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 7 AD7524M Advanced LinCMOS 8-BIT MULTIPLYING DIGITAL-TO-ANALOG CONVERTER SGLS028A – SEPTEMBER 1989 – REVISED MARCH 1995 PRINCIPLES OF OPERATION Data Bus D0 – D7 6800 DB0 – DB7 Φ2 WR AD7524M OUT1 OUT2 CS Decode Logic VMA A0 – A15 Address Bus Figure 5. AD7524M – 6800 Interface A8 – A15 Address Bus Decode Logic 8-Bit Latch 8051 CS WR DB0 – DB7 WR Address / Data Bus Figure 6. AD7524M–8051 Interface 8 OUT1 OUT2 ALE AD0 – AD7 AD7524M POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. 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