WM2604

WM2604 Quad 10-Bit Serial Input Voltage Output DAC Production Data, June 1999, Rev 1.0 FEATURES • • • • Four 10-bit voltage output DACs Dual 2.7V to 5.5V supply (separate digital and analogue supplies) DNL ± 0.1 LSB, INL ± 0.4 LSB Low power consumption: - 5.5mW, slow mode - 5V supply - 3.3mW, slow mode - 3V supply TMS320, (Q)SPI™ , and Microwire™ compatible serial interface Programmable settling time of 4µ s or 12µ s typical DESCRIPTION The WM2604 is a quadruple 10-bit voltage output, resistor string, digital-to-analogue converter. Each DAC can be individually powered down under software control. A hardware controlled mode is provided that powers down all DACs. Power down reduces current consumption to 10nA. The device has been designed to interface efficiently to industry standard microprocessors and DSPs, including the TMS320 family. The WM2604 is programmed with a 16-bit serial word comprising of a DAC address, individual DAC control bits and a 10-bit value. The WM2604 has provision for two supplies: one supply for the serial interface (DVDD, DGND), and one for the DACs, reference buffers and output buffers (AVDD, AGND). This enables a typical application where the device can be controlled via a microprocessor operating on a 3V supply, with the DACs operating on a 5V supply. Alternatively, the supplies can be tied together in a single supply application. Excellent performance is delivered with a typical DNL of ±0.1 LSB. The settling time of the DAC is programmable to allow the designer to optimize speed versus power dissipation. The output stage is buffered by a x2 gain near rail-to-rail amplifier, which features a Class AB output stage. DACs A and B can have a different reference voltage to DACs C and D. The device is available in a 16-pin TSSOP package. Commercial temperature (0° to 70°C) and Industrial temperature (-40° to 85°C) variants are supported. • • APPLICATIONS • • • • • • • Battery powered test instruments Digital offset and gain adjustment Battery operated/remote industrial controls Machine and motion control devices Wireless telephone and communication systems Speech synthesis Arbitrary waveform generation ORDERING INFORMATION DEVICE WM2604CDT WM2604IDT TEMP. RANGE 0° to 70°C -40° to 85°C PACKAGE 16-pin TSSOP 16-pin TSSOP BLOCK DIAGRAM AVDD (16) DVDD (1) REFINAB (15) REFINCD (10) DAC A REFERENCE INPUT BUFFER X1 DAC OUTPUT BUFFER X2 (14) OUTA TYPICAL PERFORMANCE 1 AVDD = DVDD =5V, VREF = 2.048V, Speed = Fast mode, Load = 10k/100pF 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 DAC B (13) OUTB WM2604 DIN (4) data FS (7) 16-BIT SHIFT REGISTER AND CONTROL LOGIC 12-BIT DATA AND CONTROL HOLDING LATCH SCLK (5) NCS (6) 2-BIT CONTROL LATCH POWERDOWN/ SPEED CONTROL DNL (LSB) (12) OUTC 10-BIT DAC LATCH -0.8 -1 0 256 512 CODE 767 1023 DAC C POWER-ON RESET DAC D (11) OUTD (9) AGND (8) DGND (3) NLDAC (2) NPD WOLFSON MICROELECTRONICS LTD Lutton Court, Bernard Terrace, Edinburgh, EH8 9NX, UK Tel: +44 (0) 131 667 9386 Fax: +44 (0) 131 667 5176 Email: sales@wolfson.co.uk http://www.wolfson.co.uk Production Data Datasheets contain final specifications current on publication date. Supply of products conforms to Wolfson Microelectronics' Terms and Conditions. ©1999 Wolfson Microelectronics Ltd. WM2604 Production Data PIN CONFIGURATION DVDD NPD NLDAC DIN SCLK NCS FS DGND 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 AVDD REFINAB OUTA OUTB OUTC OUTD REFINCD AGND PIN DESCRIPTION PIN NO 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 NAME DVDD NPD NLDAC DIN SCLK NCS FS DGND AGND REFINCD OUTD OUTC OUTB OUTA REFINAB AVDD TYPE Supply Digital input Digital input Digital input Digital input Digital input Digital input Ground Ground Analogue input Analogue output Analogue output Analogue output Analogue output Analogue input Supply DESCRIPTION Digital supply. Power down. Powers down all DACs overriding their individual power down settings and all output stages. This pin is active low. Load DAC. Digital input active low. NLDAC must be taken low to update the DAC latch from the holding latches. Serial data input. Serial clock input. Chip select. This pin is active low. Frame synchronisation for serial input data. Digital ground. Analogue ground. Voltage reference input for DACs C and D. DAC D output. DAC C output. DAC B output. DAC A output. Voltage reference input for DACs A and B. Analogue supply. WOLFSON MICROELECTRONICS LTD PD Rev 1.0 June 1999 2 WM2604 Production Data ABSOLUTE MAXIMUM RATINGS Absolute Maximum Ratings are stress ratings only. Permanent damage to the device may be caused by continuously operating at or beyond these limits. Device functional operating limits and guaranteed performance specifications are given under Electrical Characteristics at the test conditions specified ESD Sensitive Device. This device is manufactured on a CMOS process. It is therefore generically susceptible to damage from excessive static voltages. Proper ESD precautions must be taken during handling and storage of this device. CONDITION Supply voltages, AVDD to AGND, DVDD to DGND Supply voltage differences, AVDD to DVDD Digital input voltage Reference input voltage Operating temperature range, TA Storage temperature Lead temperature 1.6mm (1/16 inch) soldering for 10 seconds WM2604C WM2604I -2.8V -0.3V -0.3V 0°C -40°C -65°C MIN MAX 7V 2.8V DVDD + 0.3V AVDD + 0.3V 70°C 85°C 150°C 260°C RECOMMENDED OPERATING CONDITIONS PARAMETER Supply voltage High-level digital input voltage Low-level digital input voltage Reference voltage to REFINAB, REFINCD Load resistance Load capacitance Serial clock rate Operating free-air temperature SYMBOL AVDD, DVDD VIH VIL VREF RL CL fSCLK TA WM2604CDT WM2604IDT 0 -40 DVDD = 2.7V to 5.5V DVDD = 2.7V to 5.5V See Note 2 10 100 20 70 85 TEST CONDITIONS MIN 2.7 2 0.8 AVDD - 1.5 TYP MAX 5.5 UNIT V V V V kΩ pF MHz °C °C Note: Reference voltages greater than AVDD/2 will cause output saturation for large DAC codes. WOLFSON MICROELECTRONICS LTD PD Rev 1.0 June 99 3 WM2604 Production Data ELECTRICAL CHARACTERISTICS Test Conditions: RL = 10kΩ, CL = 100pF. AVDD = DVDD = 5V ± 10%, VREF = 2.048V and AVDD = DVDD = 3V ± 10%, VREF = 1.024V over recommended operating free-air temperature range (unless noted otherwise). PARAMETER Static DAC Specifications Resolution Integral non-linearity Differential non-linearity Zero code error Gain error d.c. power supply rejection ratio Zero code error temperature coefficient Gain error temperature coefficient DAC Output Specifications Output voltage range Output load regulation Power Supplies Active supply current IDD No load, VIH = DVDD, VIL = 0V AVDD = 5V, VREF = 2.048V Slow AVDD = 5V, VREF = 2.048V Fast AVDD = 3V, VREF = 1.024V Slow AVDD = 3V, VREF = 1.024V Fast See Note 8 Power down supply current No load, all digital inputs 0V or DVDD See Note 9 Dynamic DAC Specifications Slew rate DAC code 32 to 1023, 10% to 90% Slow Fast See Note 10 Settling time DAC code 32 to 1023 Slow Fast See Note 11 Glitch energy Signal to noise ratio SNR Code 511 to 512 fs = 400ksps, fOUT = 1kHz, BW = 20kHz See Note 12 Signal to noise and distortion ratio SNRD fs = 400ksps, fOUT = 1kHz, BW = 20kHz See Note 12 Total harmonic distortion THD fs = 400ksps, fOUT = 1kHz, BW = 20kHz See Note 12 Spurious free dynamic range SPFDR fs = 400ksps, fOUT = 1kHz, BW = 20kHz See Note 12 WOLFSON MICROELECTRONICS LTD PD Rev 1.0 June 1999 4 54 70 dB -68 -54 dB 54 65 dB 60 10 68 nV-s dB 12.0 4.0 µs µs 0.5 2.5 1.0 4.0 V/µ s V/µ s 0.01 10 µA 1.4 3.5 1.0 3.0 2.2 5.5 1.5 4.5 mA 2kΩ to 10kΩ load See Note 7 0 0.1 AVDD - 0.1 0.25 V % INL DNL ZCE GE DC PSRR See Note 1 See Note 2 See Note 3 See Note 4 See Note 5 See Note 6 See Note 6 10 bits SYMBOL TEST CONDITIONS MIN TYP MAX UNIT ± 0.4 ± 0.1 3 0.25 0.5 10 10 ±1 ± 0.25 ± 12 ± 0.6 LSB LSB mV % FSR mV/V ppm/°C ppm/°C WM2604 Production Data Test Conditions: RL = 10kΩ, CL = 100pF. AVDD = DVDD = 5V ± 10%, VREF = 2.048V and AVDD = DVDD = 3V ± 10%, VREF = 1.024V over recommended operating free-air temperature range (unless noted otherwise). PARAMETER Reference Reference input resistance Reference input capacitance Reference feedthrough Reference input bandwidth RREFIN CREFIN VREF = 1VPP at 1kHz + 1.024V dc, DAC code 0 VREF = 0.2VPP + 1.024V dc DAC code 512 Slow Fast Digital Inputs High level input current Low level input current Input capacitance Notes: 1. Integral non-linearity (INL) is the maximum deviation of the output from the line between zero and full scale (excluding the effects of zero code and full scale errors). 2. Differential non-linearity (DNL) is the difference between the measured and ideal 1LSB amplitude change of any adjacent two codes. A guarantee of monotonicity means the output voltage changes in the same direction (or remains constant) as a change in digital input code. 3. Zero code error is the voltage output when the DAC input code is zero. 4. Gain error is the deviation from the ideal full scale output excluding the effects of zero code error. 5. Power supply rejection ratio is measured by varying AVDD from 4.5V to 5.5V and measuring the proportion of this signal imposed on the zero code error and the gain error. 6. Zero code error and Gain error temperature coefficients are normalised to full scale voltage. 7. Output load regulation is the difference between the output voltage at full scale with a 10kΩ load and 2kΩ load. It is expressed as a percentage of the full scale output voltage with a 10kΩ load. 8. IDD is measured while continuously writing code 512 to the DAC. For VIH < DVDD - 0.7V and VIL > 0.7V supply current will increase. 9. Typical supply current in power down mode is 10nA. Production test limits are wider for speed of test. 10. Slew rate results are for the lower value of the rising and falling edge slew rates. 11. Settling time is the time taken for the signal to settle to within 0.5LSB of the final measured value for both rising and falling edges. Limits are ensured by design and characterisation, but are not production tested. 12. SNR, SNRD, THD and SPFDR are measured on a synthesised sinewave at frequency fOUT generated with a sampling frequency fs. IIH IIL CI Input voltage = DVDD Input voltage = 0V 3 1 -1 µA µA pF 0.5 1 MHz MHz 10 5 -75 MΩ pF dB SYMBOL TEST CONDITIONS MIN TYP MAX UNIT WOLFSON MICROELECTRONICS LTD PD Rev 1.0 June 99 5 WM2604 Production Data SERIAL INTERFACE tWL SCLK 1 tSUD DIN D15 tSUCSFS NCS tWHFS FS tSUFSCLK tSUC16FS tHD D14 D13 D12 D1 D0 2 tWH 3 4 5 15 16 tSUC16CS Figure 1 Timing Diagram Test Conditions: RL = 10kΩ, CL = 100pF. AVDD = DVDD = 5V ± 10%, VREF = 2.048V and AVDD = DVDD = 3V ± 10%, VREF = 1.024V over recommended operating free-air temperature range (unless noted otherwise) SYMBOL tSUCSFS tSUFSCLK tSUC16FS TEST CONDITIONS Setup time NCS low before negative FS edge. Setup time FS low before first negative SCLK edge. Setup time, sixteenth negative SCLK edge after FS low on which D0 is sampled before rising edge of FS. Setup time, sixteenth positive SCLK edge (first positive after D0 sampled) before NCS rising edge. If FS is used instead of the sixteenth positive edge to update the DAC, then the setup time is between the FS rising edge and the NCS rising edge. Pulse duration, SCLK high. Pulse duration, SCLK low. Setup time, data ready before SCLK falling edge. Hold time, data held valid after SCLK falling edge. Pulse duration, FS high. MIN 10 8 10 10 TYP MAX UNIT ns ns ns ns tSUC16CS tWHCLK tWLCLK tSUDCLK tHDCLK tWHFS 25 25 8 5 20 ns ns ns ns ns WOLFSON MICROELECTRONICS LTD PD Rev 1.0 June 1999 6 WM2604 Production Data TYPICAL PERFORMANCE GRAPHS 1 AVDD = DVDD =5V, VREF =2.048V, Speed = Fast mode, Load = 10k/100pF 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1 0 256 512 DIGITAL CODE INL - LSB 767 1023 Figure 2 Integral Non-Linearity 0.4 0.4 AVDD = DVDD = 3V, VREF = 1V, Input Code = 0 0.35 0.35 AVDD = DVDD = 5V, VREF = 2V, Input Code = 0 0.3 OUTPUT VOLTAGE - V 0.3 OUTPUT VOLTAGE - V 0.25 0.25 0.2 0.2 0.15 0.15 0.1 0.1 0.05 0.05 0 0 0 1 2 3 4 5 ISINK - mA 6 7 8 Slow 0 9 Fast 1 2 3 4 5 ISINK - mA 6 7 8 9 Slow Fast 10 10 Figure 3 Sink Current AVDD = DVDD = 3V 2.054 Figure 4 Sink Current AVDD = DVDD = 5V 4.092 AVDD = DVDD = 3V, VREF = 1V, Input Code = 1023 2.052 2.05 2.048 OUTPUT VOLTAGE - V 4.09 4.088 4.086 4.084 4.082 4.08 4.078 4.076 AVDD = DVDD = 5V, V REF = 2V, Input Code = 1023 OUTPUT VOLTAGE - V 2.046 2.044 2.042 2.04 2.038 4.074 2.036 2.034 2.032 0 1 2 3 4 5 6 7 8 9 10 4.072 4.07 0 1 2 3 4 5 ISOURCE - mA 6 7 8 Slow 9 10 Fast ISOURCE - mA Slow Fast Figure 5 Source Current AVDD = DVDD = 3V Figure 6 Sink Current AVDD = DVDD = 5V WOLFSON MICROELECTRONICS LTD PD Rev 1.0 June 99 7 WM2604 Production Data DEVICE DESCRIPTION GENERAL FUNCTION The device uses a resistor string network buffered with an op amp to convert 10-bit digital data to analogue voltage levels (see Block Diagram). The output voltage is determined by the reference input voltage and the input code according to the following relationship: Output voltage = 2(VREF ) INPUT 11 1111 : 10 10 01 0000 0000 1111 : 00 00 0000 0000 0001 0000 0001 0000 1111 1111 CODE 1024 OUTPUT 2(VREF ) : 2(VREF ) 2(VREF ) 513 1024 1023 1024 512 = VREF 1024 511 1024 1 1024 2(VREF ) : 2(VREF ) 0V Table 1 Binary Code Table (0V to 2VREFIN Output), Gain = 2 POWER ON RESET An internal power-on-reset circuit resets the DAC registers to all 0s on power-up. BUFFER AMPLIFIER The output buffer has a near rail-to-rail output with short circuit protection and can reliably drive a 2kΩ load with a 100pF load capacitance. EXTERNAL REFERENCE The reference voltage input is buffered which makes the DAC input resistance independent of code. REFINAB and REFINCD pins have an input resistance of 10MΩ and an input capacitance of typically 5pF. The reference voltage determines the DAC full-scale output. HARDWARE CONFIGURATION OPTIONS The device has two configuration options that are controlled by device pins. DEVICE POWER DOWN The device can be powered-down by pulling pin NPD (Pin 2) high. This powers down all DACs overriding their individual power down settings. This will reduce power consumption to typically 10nA. When the power down function is released the device reverts to the DAC code set prior to power down. SIMULTANEOUS DAC UPDATE The NLDAC pin (Pin 3) can be held high to prevent serial word writes from updating the DAC latches. By writing new values to multiple DACs then pulling NLDAC low, all new DAC codes are loaded into the DAC latches simultaneously. WOLFSON MICROELECTRONICS LTD PD Rev 1.0 June 1999 8 WM2604 Production Data SERIAL INTERFACE Explanation of data transfer: First, the device has to be enabled with NCS set to low. Then, a falling edge of FS starts shifting the data bit-per-bit (starting with the MSB) to the internal register on the falling edges of SCLK. After 16 bits have been transferred, the next rising edge on SCLK or FS causes the content of the shift register to be moved to the DAC holding latch. If NLDAC is low, the DAC latch will also be updated immediately. The serial interface of the device can be used in two basic modes: • • four wire (with chip select) three wire (without chip select) Using chip select (four wire mode), it is possible to have more than one device connected to the serial port of the data source (DSP or microcontroller). If there is no need to have more than one device on the serial bus, then NCS can be tied low. SERIAL CLOCK AND UPDATE RATE Figure 1 shows the device timing. The maximum serial rate is: fSCLKmax = 1 = 20MHz tWCH min + tWCL min The digital update rate is limited to an 800ns period, or 1.25MHz frequency. However, the DAC settling time to 10 bits limits the update rate for large input step transitions. SOFTWARE CONFIGURATION OPTIONS The 16 bits of data can be transferred with the sequence shown in Table 2. D11-D2 contains the 10-bit data word. D15-D12 hold the programmable options. D15 A1 D14 A0 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 X D0 X PWR SPD New DAC value (10 bits) Table 2 Register Map DAC ADDRESSING A particular DAC (A, B, C, D) within the device is selected by A1 and A0 within the input word. A1 0 0 1 1 A0 0 1 0 1 DAC ADDRESS DAC A DAC B DAC C DAC D PROGRAMMABLE SETTLING TIME (SPD – BIT D12) Settling time is a software selectable 12µ s or 4µ s, typical to within ±0.5LSB of final value. This is controlled by the value of SPD – Bit D12 and an associated DAC address. A ONE defines a settling time of 4µ s, a ZERO defines a settling time of 12µ s for that DAC. PROGRAMMABLE POWER DOWN The power down function is controlled by PWR - Bit D13 and an associated DAC address. A ZERO configures that DAC as active, a ONE configures that DAC into power down mode. WOLFSON MICROELECTRONICS LTD PD Rev 1.0 June 99 9 WM2604 Production Data PACKAGE DIMENSIONS DT: 16 PIN TSSOP (5.0 x 4.4 x 1.0 mm ) DM013.A b 16 e 9 E1 E GAUGE PLANE 1 8 θ D 0.25 c A A2 A1 L -C0.05 C SEATING PLANE Symbols A A1 A2 b c D e E E1 L θ REF: MIN ----0.05 0.80 0.19 0.09 4.90 4.30 0.45 o 0 Dimensions (mm) NOM --------1.00 --------5.00 0.65 BSC 6.4 BSC 4.40 0.60 ----JEDEC.95, MO-153 MAX 1.20 0.15 1.05 0.30 0.20 5.10 4.50 0.75 o 8 NOTES: A. ALL LINEAR DIMENSIONS ARE IN MILLIMETERS. B. THIS DRAWING IS SUBJECT TO CHANGE WITHOUT NOTICE. C. BODY DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSION, NOT TO EXCEED 0.25MM. D. MEETS JEDEC.95 MO-153, VARIATION = AB. REFER TO THIS SPECIFICATION FOR FURTHER DETAILS. WOLFSON MICROELECTRONICS LTD PD Rev 1.0 June 1999 10