ML2008IQ

March 1997 ML2008*, ML2009** µP Compatible Logarithmic Gain/Attenuator GENERAL DESCRIPTION The ML2008 and ML2009 are digitally controlled logarithmic gain/attenuators with a range of –24 to +24dB in 0.1dB steps. Easy interface to microprocessors is provided by an input latch and control signals consisting of chip select and write. The interface for gain setting of the ML2008 is by an 8-bit data word, while the ML2009 is designed to interface to a 16-bit data bus with a single write operation by hardwiring the gain/attenuation pin or LSB pin. The ML2008 can be power downed by the microprocessor utilizing a bit in the second write operation. Absolute gain accuracy is 0.05dB max over supply tolerance of ± 10% and temperature range. These CMOS logarithmic gain/attenuators are designed for a wide variety of applications in telecom, audio, sonar or general purpose function generation. * This Part Is End Of Life As Of August 1, 2000 ** This Part Is Obsolete FEATURES s s s s s s s s Low noise 0dBrnc max with +24dB gain Low harmonic distortion –60dB max Gain range –24 to +24dB Resolution 0.1dB steps Flat frequency response ± 0.05dB from 0.3-4kHz ± 0.10dB from 0.1-20kHz Low supply current 4mA max from ± 5V supplies TTL/CMOS compatible digital interface ML2008 is designed to interface to an 8-bit data bus; ML2009 to 16-bit data bus BLOCK DIAGRAM ML2008 VCC VSS GND AGND VCC VSS GND ML2009* AGND +5 VIN –5 + COARSE – + FINE – RESISTORS/ SWITCHES 16 DECODERS 8 REGISTER 0 + BUFFER – VOUT +5 VIN –5 + COARSE – + FINE – RESISTORS/ SWITCHES 16 DECODERS 9 RESISTORS/ SWITCHES 16 + BUFFER – VOUT RESISTORS/ SWITCHES 16 1 PDN 1 REGISTER 1 8 WR CS A0 WR CS REGISTER 0 9 D0–D8 D1–D8 1 ML2008, ML2009 PIN CONFIGURATION ML2008 18-Pin DIP (P18) D7 D6 D5 D4 WR D3 D2 D1 GND 1 2 3 4 5 6 7 8 9 18 17 16 15 14 13 12 11 10 TOP VIEW D8 VCC VOUT VSS AGND VIN NC CS A0 D7 D6 D5 D4 WR D3 D2 D1 GND ML2009* 18-Pin DIP (P18) 1 2 3 4 5 6 7 8 9 18 17 16 15 14 13 12 11 10 TOP VIEW D8 VCC VOUT VSS AGND VIN NC CS D0 20-Pin PLCC (Q20) VCC D5 D6 D7 D8 20-Pin PLCC (Q20) VCC 19 18 17 16 15 14 9 D1 10 11 GND D0 12 CS 13 VIN VOUT VSS AGND NC NC D5 D6 D7 1 D8 20 3 D4 NC WR D3 D2 4 5 6 7 8 9 D1 2 1 20 19 18 17 16 15 14 VOUT VSS AGND NC NC D4 NC WR D3 D2 4 5 6 7 8 3 2 10 11 GND A0 12 CS 13 VIN TOP VIEW TOP VIEW PIN DESCRIPTION NAME FUNCTION NAME FUNCTION VSS VCC GND AGND Negative supply. –5Volts ± 10% Positive supply. 5Volts ± 10% Digital ground. 0Volts. All digital inputs are referenced to this ground. Analog ground. 0Volts. Analog input and output are referenced to this ground. Analog input Analog output Data bit, ATTEN/ GAIN Data bit, C3 Data bit, C2 Data bit, C1 Data bit, C0 D3 D2 D1 D0 WR CS Data bit, F3 Data bit, PDN, F2 ML2008; F2 ML2009 Data bit, F0, F1 ML2008; F1 ML2009 Data bit, F0 ML2009 only Write enable. This input latches the data bits into the registers on rising edges of WR . Chip select. This input selects the device by only allowing the WR signal to latch in data when CS is low. Address select. This input determines which data word is being written into the registers. VIN VOUT D8 D7 D6 D5 D4 A0 (ML2008 only) 2 ML2008, ML2009 ABSOLUTE MAXIMUM RATINGS (Note 1) Supply Voltage VCC .................................................................... +6.5V VSS ......................................................................–6.5V AGND with Respect to GND....................... V CC to VSS Analog Inputs and Outputs ..... VSS –0.3V to VCC +0.3V Digital Inputs and Outputs ... GND –0.3V to VCC +0.3V Input Current Per Pin ........................................ ± 25mA Power Dissipation ........................................... 750mW Storage Temperature Range ............... –65°C to +150°C Lead Temperature (Soldering 10 sec.) ................. 300 °C OPERATING CONDITIONS Temperature Range (Note 2) ML2008CX, ML2009CX .......................... 0°C to +70°C ML2008IX, ML2009IX ......................... –40°C to +85°C Supply Voltage VCC ................................................................ 4V to 6V VSS ............................................................. –4V to –6V ELECTRICAL CHARACTERISTICS Unless otherwise specified, TA = TMIN to TMAX, VCC = 5V ± 10%, VSS = –5V ± 10%, Data Word: D8 (ATTEN/GAIN) = 1, Other Bits = 0, (0dB Ideal Gain), CL = 100pF, R L = 600Ω, dBm measurements use 600 Ω as reference load, digital timing measured at 1.4V. SYMBOL Analog AG RG Absolute Gain Accuracy Relative Gain Accuracy 4 4 VIN = 8dBm, 1kHz 100000001 000000000 000000001 All other gain settings All values referenced to 100000000 gain when D8 (ATTEN/GAIN) = 1, VIN = 8dBm when D8 (ATTEN/GAIN) = 0, VIN = (8dBm – Ideal Gain) in dB 300-4000Hz 100-20,000Hz Relative to 1kHz VIN = 0, +24dB gain VIN = 0, +24dB, C msg weighted VIN = 0, +24dB, 1kHz VIN = 8dBm, 1kHz Measure 2nd, 3rd, harmonic relative to fundamental VIN = 8dBm, 1kHz C msg weighted 200mVP-P, 1kHz sine, VIN = 0 on VCC on VSS 1 ± 3.0 ± 3.0 +60 –6 450 –0.05 –0.05 –0.05 –0.05 –0.1 +0.05 +0.05 +0.05 +0.05 +0.1 dB dB dB dB dB PARAMETER NOTES CONDITIONS MIN TYP NOTE 3 MAX UNITS FR Frequency Response 4 –0.05 –0.1 +0.05 +0.1 ±100 0 900 –60 dB dB mV dBrnc nv/√Hz dB VOS ICN HD Output Offset Voltage Idle Channel Noise Harmonic Distortion 4 4 5 4 SD PSRR Signal to Distortion Power Supply Rejection 4 4 dB –60 –60 –40 –40 dB dB Meg V V ZIN VINR VOSW Input Impedance, VIN Input Voltage Range Output Voltage Swing 4 4 4 3 ML2008, ML2009 ELECTRICAL CHARACTERISTICS (Continued) SYMBOL Digital and DC VIL VIH IIN IIN ICC ISS ICCP ISSP Digital Input Low Voltage Digital Input High Voltage Input Current, Low Input Current, High VCC Supply Current VSS Supply Current VCC Supply Current, ML2008 Powerdown Mode Only VSS Supply Current, ML2008 Powerdown Mode Only 4 4 4 4 4 4 4 4 VIH = GND VIH = VCC No output load, VIL = GND, VIH = VCC, VIN = 0 No output load, VIL = GND, VIH = VCC, VIN = 0 No output load, VIL = GND, VIH = VCC No output load, VIL = GND, VIH = VCC VIN = 0.185V. Change gain from –24 to +24dB. Measure from WR rising edge to when VOUT settles to within 0.05dB of final value. Gain = +24dB. VIN = –3V to +3V step. Measure from VIN = –3V to when VOUT settles to within 0.05dB of final value. 50 50 0 0 0 0 50 2.0 –10 10 4 –4 0.5 –0.1 0.8 V V µA µA mA mA mA mA PARAMETER NOTES CONDITIONS MIN TYP NOTE 3 MAX UNITS AC Characteristics tSET VOUT Settling Time 4 20 µs tSTEP VOUT Step Response 4 20 µs tDS tDH tAS tAH tCSS tCSH tPW Note 1: Note 2: Note 3: Note 4: Note 5: Data Setup Time Data Hold Time A0 Setup Time A0 Hold Time CS* Setup Time CS* Hold Time WR* Pulse Width 4 4 4 4 4 4 4 ns ns ns ns ns ns ns Absolute maximum ratings are limits beyond which the life of the integrated circuit may be impaired. All voltages unless otherwise specified are measured with respect to ground. 0°C to +70°C and –40°C to +85°C operating temperature range devices are 100% tested with temperature limits guaranteed by 100% testing, sampling, or by correlation with worst-case test conditions. Typicals are parametric norm at 25°C. Parameter guaranteed and 100% production tested. Parameter guaranteed. Parameters not 100% tested are not in outgoing quality level calculation. 4 ML2008, ML2009 TIMING DIAGRAM D0-D8 tDS tPW WR tAS A0 tCSS CS tCSH tAH DATA VALID tDH TYPICAL PERFORMANCE CURVES 0 –0.5 –.10 –.15 AMPLITUDE (dB) GAIN = +18dB ATTEN: VIN = 0.5VRMS GAIN: VIN = 0.5VRMS/GAIN SETTING GAIN = +24dB –.20 GAIN = +12dB –.25 GAIN = +0, –24dB –.30 –.35 –.40 –.45 –.50 100 1K 10K FREQUENCY (Hz) 100K 0 –0.5 –.10 –.15 AMPLITUDE (dB) ATTEN: VIN = 2VRMS GAIN: VIN = 2VRMS/GAIN SETTING GAIN = +24dB GAIN = 0dB –.20 GAIN = –24dB –.25 –.30 –.35 –.40 –.45 –.50 100 1K 10K FREQUENCY (Hz) 100K Figure 2. Amplitude vs Frequency (VIN/VOUT = 0.5VRMS) Figure 3. Amplitude vs Frequency (VIN/VOUT = 2VRMS) 2 OUTPUT NOISE VOLTAGE (µV/√Hz) 1.8 CMSG OUTPUT (NOISE) (dBrnc) 1.6 1.4 GAIN = +12dB 1.2 1 0.8 0.6 0.4 0.2 0 GAIN = –24dB GAIN = +24dB –2 VIN = 0 –3 –4 –5 –6 –7 –8 –9 –10 10 100 FREQUENCY (Hz) 1K 10K –24 –18 –12 –6 0 6 12 18 24 GAIN SETTING (dB) Figure 4. Output Noise Voltage vs Frequency Figure 5. CMSG Output Noise vs Gain Setting 5 ML2008, ML2009 TYPICAL PERFORMANCE CURVES (Continued) 100 ATTEN: VIN = 8dBm GAIN: VIN = 8dBm/GAIN SETTING 1kHZ GAIN ERROR (dB) 0.1 .08 .06 .04 .02 0 –.02 –.04 90 CMSG S/N (DB) 80 70 60 50 –.06 –.08 40 –24 –18 –12 –6 0 6 12 18 24 –1.0 –24 –18 –12 –6 0 6 12 18 24 GAIN SETTING (dB) GAIN SETTING (dB) Figure 6. CMSG S/N vs Gain Setting 80 VIN = 1kHz 70 60 S/N + D (dB) 50 40 30 VIN = 50kHz 20 ATTEN: V = 2V IN RMS GAIN: VIN = 2VRMS/GAIN SETTING 10 –24 –18 –12 –6 0 30 VIN = 20kHz S/N + D (dB) 70 Figure 7. Gain Error vs Gain Setting 80 VIN = 1kHz VIN = 20kHz 60 VIN = 50kHz 50 40 ATTEN: VIN = 0.5VRMS GAIN: VIN = 0.5VRMS/GAIN SETTING –18 –12 –6 0 6 12 18 24 6 12 18 24 20 –24 GAIN SETTING (dB) GAIN SETTING (dB) Figure 8. S/N +D vs Gain Setting (VIN/V OUT = 2VRMS) Figure 9. S/N +D vs Gain Setting (VIN/VOUT = 0.5VRMS) 1.0 FUNCTIONAL DESCRIPTION The ML2008, ML2009 consists of a coarse gain stage, a fine gain stage, an output buffer, and a µP compatible parallel digital interface. 1.1 Gain Stages The analog input, VIN, goes directly into the op amp input in the coarse gain stage. The coarse gain stage has a gain range of 0 to 22.5dB in 1.5dB steps. The fine gain stage is cascaded onto the coarse section. The fine gain stage has a gain range of 0 to 1.5dB in 0.1dB steps. Both stages can be programmed for either gain or attenuation, thus doubling the effective gain range. The logarithmic steps in each gains stage are generated by placing the input signal across a resistor string of 16 series resistors. Analog switches allow the voltage to be tapped from the resistor string at 16 points. The resistors are sized such that each output voltage is at the proper logarithmic ratio relative to the input signal at the top of the string. Attenuation is implemented by using the resistor string as a simple voltage divider, and gain is implemented by using the resistor string as a feedback resistor around an internal op amp. 1.2 Gain Settings Since the coarse and fine gain stages are cascaded, their gains can be summed logarithmically. Thus, any gain from –24dB to +24dB in 0.1dB steps can be obtained by combining the coarse and fine gain setting to yield the 6 ML2008, ML2009 desired gain setting. The relationship between the register 0 and 1 bits and the corresponding analog gain values is shown in Tables 1 and 2. Note that C3-C0 select the coarse gain, F3-F0 select the fine gain, and ATTEN/GAIN selects either gain or attenuation. 1.3 Output Buffer The final analog stage is the output buffer. This amplifier has internal gain of 1 and is designed to drive 600Ω, 100pF loads. Thus, it is suitable for driving a telephone hybrid circuit directly without any external amplifier. 1.4 Power Supplies The digital section is powered between VCC and GND, or 5V. The analog section is powered between V CC and VSS and uses AGND as the reference point, or ± 5V. GND and AGND are totally isolated inside the device to minimize coupling from the digital section into the analog section. Typically this is less than 100µV. However, AGND and GND should be tied together physically near the device and ideally close to the common power supply ground connection. Typically, the power supply rejection of VCC and VSS to the analog output is greater than –60dB at 1KHz. If decoupling of the power supplies is still necessary in a system, VCC and VSS should be decoupled with respect to AGND. Table 1. Fine Gain Settings (C3 – C0 = 0) F3 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 F2 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 F1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 F0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 Ideal Gain (dB) ATTEN/GAIN = 1 ATTEN/GAIN = 0 0.0 –0.1 –0.2 –0.3 –0.4 –0.5 –0.6 –0.7 –0.8 –0.9 –1.0 –1.1 –1.2 –1.3 –1.4 –1.5 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 Table 2. Coarse Gain Settings (F3 – F0 = 0) C3 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 C2 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 C1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 C0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 Ideal Gain (dB) ATTEN/GAIN = 1 ATTEN/GAIN = 0 0.0 –1.5 –3.0 –4.5 –6.0 –7.5 –9.0 –10.5 –12.0 –13.5 –15.0 –16.5 –18.0 –19.5 –21.0 –22.5 0.0 1.5 3.0 4.5 6.0 7.5 9.0 10.5 12.0 13.5 15.0 16.5 18.0 19.5 21.0 22.5 2.0 DIGITAL INTERFACE The architecture of the digital section is shown in the preceding black diagram. The structure of the data registers or latches is shown in Figures 10 and 11 for the ML2008 and ML2009, respectively. The registers control the attenuation/gain setting bits and with the ML2008 the power down bit. Tables 1 and 2 describe how the data word programs the gain. The difference between the ML2008 and ML2009 is in the register structure. The ML2008 is an 8-bit data bus version. This device has one 8-bit register and one 2-bit register to store the 9 gain setting bits and 1 powerdown bit. Two write operations are necessary to program the full 10 data bits from eight external data pins. The address pin A0 controls which register is being written into. The powerdown bit, PDN, causes the device to be placed in powerdown. When PDN = 1, the device is powered down. In this state, the power consumption is reduced by removing power from the analog section and forcing the analog output, VOUT, to a high impedance state. While the device is in powerdown, the digital section is still functional and the current data word remains stored in the registers. When PDN = 0, device is in normal operation. The ML2009 is a 9-bit data bus version. This device has one 9-bit register to store the 9 gain setting bits. The full 9 data bits can be programmed with one write operation from nine external data pins. The internal registers or latches are edge triggered. The data is transferred from the external pins to the register output on the rising edge of WR. The address pin, A0, controls which register the data will be written into as shown in Figures 1 and 2. The CS control signal selects the device by allowing the WR signal to latch in the data only when CS is low. When CS is high, WR is inhibited from latching in new data into the registers. 7 ML2008, ML2009 D8 A0 = 0 A0 = 1 ATTEN/GAIN D7 C3 D6 C2 D5 C1 D4 C0 D3 F3 D2 F2 PDN D1 F1 F0 BIT REG 0 REG 1 D8 ATTEN/GAIN D7 C3 D6 C2 D5 C1 D4 C0 D3 F3 D2 F2 D1 D0 F1 F0 BIT REG 0 Figure 10. ML2008 Register Structure Figure 11. ML2009 Register Structure ML2008 VIN VOUT VIN ML2009 VOUT CS WR A0 D1-D8 CS WR D1-D8 D0 +5V µP 8 µP 8 Figure 12. Typical 8-Bit µP Interface, Double Write Figure 13. Typical 8-Bit µP Interface, Single Write ML2009 VIN ML2009 VOUT VIN D0-D8 WR CS ML2233 12-BIT + SIGN A/D µP OR DSP CS WR D0-D8 µP 9 Figure 14. Typical 16-Bit µP Interface Figure 15. AGC for DSP or Modem Front End 8 ML2008, ML2009 +5V ML2008 VIN D1-D8 CS A0 VIN ML2009 VOUT D0-D8 –5V ADDRESS µP D E CS1 C O CS2 D E R A0 WR D1-D8 CS A0 ML2008 2.5V REF Figure 16. Operation as Logarithmic D/A Converter Figure 17. Controlling Multiple Gain/Attenuators 9 ML2008, ML2009 PHYSICAL DIMENSIONS inches (millimeters) Package: Q20 20-Pin PLCC 0.385 - 0.395 (8.89 - 10.03) 0.350 - 0.356 (8.89 - 9.04) 1 0.042 - 0.056 (1.07 - 1.42) 0.025 - 0.045 (0.63 - 1.14) (RADIUS) 0.042 - 0.048 (1.07 - 1.22) 6 PIN 1 ID 16 0.350 - 0.356 (8.89 - 9.04) 0.385 - 0.395 (8.89 - 10.03) 0.200 BSC (5.08 BSC) 0.290 - 0.330 (7.36 - 8.38) 11 0.050 BSC (1.27 BSC) 0.026 - 0.032 (0.66 - 0.81) 0.165 - 0.180 (4.19 - 4.57) 0.146 - 0.156 (3.71 - 3.96) 0.009 - 0.011 (0.23 - 0.28) 0.100 - 0.110 (2.54 - 2.79) 0.013 - 0.021 (0.33 - 0.53) SEATING PLANE 10 ML2008, ML2009 PHYSICAL DIMENSIONS inches (millimeters) Package: P18 18-Pin PDIP 0.890 - 0.910 (22.60 - 23.12) 18 PIN 1 ID 0.240 - 0.260 0.295 - 0.325 (6.09 - 6.61) (7.49 - 8.26) 0.045 MIN (1.14 MIN) (4 PLACES) 1 0.050 - 0.065 (1.27 - 1.65) 0.100 BSC (2.54 BSC) 0.015 MIN (0.38 MIN) 0.170 MAX (4.32 MAX) 0.125 MIN (3.18 MIN) 0.016 - 0.022 (0.40 - 0.56) SEATING PLANE 0º - 15º 0.008 - 0.012 (0.20 - 0.31) ORDERING INFORMATION PART NUMBER ML2008IP ML2008IQ ML2008CP ML2008CQ ML2009IP ML2009IQ ML2009CP ML2009CQ TEMPERATURE RANGE –40°C to 85°C –40°C to 85°C 0°C to +70°C 0°C to +70°C –40°C to 85°C –40°C to 85°C 0°C to +70°C 0°C to +70°C PACKAGE Molded PDIP (P18) (EOL) Molded PLCC (Q20) (EOL) Molded PDIP (P18) (EOL) Molded PLCC (Q20) (EOL) Molded PDIP (P18) (OBS) Molded PLCC (Q20) (OBS) Molded PDIP (P18) (OBS) Molded PLCC (Q20) (OBS) © Micro Linear 1997 is a registered trademark of Micro Linear Corporation Products described in this document may be covered by one or more of the following patents, U.S.: 4,897,611; 4,964,026; 5,027,116; 5,281,862; 5,283,483; 5,418,502; 5,508,570; 5,510,727; 5,523,940; 5,546,017; 5,559,470; 5,565,761; 5,592,128; 5,594,376; Japan: 2598946. Other patents are pending. Micro Linear reserves the right to make changes to any product herein to improve reliability, function or design. Micro Linear does not assume any liability arising out of the application or use of any product described herein, neither does it convey any license under its patent right nor the rights of others. The circuits contained in this data sheet are offered as possible applications only. Micro Linear makes no warranties or representations as to whether the illustrated circuits infringe any intellectual property rights of others, and will accept no responsibility or liability for use of any application herein. The customer is urged to consult with appropriate legal counsel before deciding on a particular application. 2092 Concourse Drive San Jose, CA 95131 Tel: 408/433-5200 Fax: 408/432-0295 DS2008_09-01 11