Datasheet

ManualsBrandsANALOG DEVICES ManualsData collecting ICsData acquisition IC - DA converter (DAC) SOIC 16

FUNCTIONAL BLOCK DIAGRAM

LATCH

DAC

SERIAL

INPUT

CONTROL

LOGIC

AD1851/

AD1861

DGND

CLK

DATA

NC = NO CONNECT

TRIM

MSB ADJ

OUT

AGND

OUT

–V

OUT

REV. A

Information furnished by Analog Devices is believed to be accurate and

reliable. However, no responsibility is assumed by Analog Devices for its

use, nor for any infringements of patents or other rights of third parties

which may result from its use. No license is granted by implication or

otherwise under any patent or patent rights of Analog Devices.

16-Bit/18-Bit, 16 3 F

PCM Audio DACs

AD1851/AD1861

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 617/329-4700 Fax: 617/326-8703

FEATURES

110 dB SNR

Fast Settling Permits 163 Oversampling

63 V Output

Optional Trim Allows Super-Linear Performance

65 V Operation

16-Pin Plastic DIP and SOIC Packages

Pin-Compatible with AD1856 & AD1860 Audio DACs

2s Complement, Serial Input

APPLICATIONS

High-End Compact Disc Players

Digital Audio Amplifiers

DAT Recorders and Players

Synthesizers and Keyboards

PRODUCT DESCRIPTION

The AD1851/AD1861 is a monolithic PCM audio DAC. The

AD1851 is a 16-bit device, while the AD1861 is an 18-bit de-

vice. Each device provides a voltage output amplifier, DAC,

serial-to-parallel register and voltage reference. The digital por-

tion of the AD1851/AD1861 is fabricated with CMOS logic

elements that are provided by Analog Devices’ 2 µm ABCMOS

process. The analog portion of the AD1851/AD1861 is fabri-

cated with bipolar and MOS devices as well as thin-film

resistors.

This combination of circuit elements, as well as careful design

and layout techniques, results in high performance audio play-

back. Laser-trimming of the linearity error affords low total har-

monic distortion. An optional linearity trim pin is provided to

allow residual differential linearity error at midscale to be elimi-

nated. This feature is particularly valuable for low distortion

reproductions of low amplitude signals. Output glitch is also

small, contributing to the overall high level of performance. The

output amplifier achieves fast settling and high slew rates, pro-

viding a full ±3 V signal at load currents up to 8 mA. When

used in current output mode, the AD1851/AD1861 provides a

±1 mA output signal. The output amplifier is short circuit

protected and can withstand indefinite shorts to ground.

The serial input interface consists of the clock, data and latch

enable pins. The serial 2s complement data word is clocked into

the DAC, MSB first, by the external clock. The latch enable

signal transfers the input word from the internal serial input

clock can support a 12.5 MHz data rate, while the AD1861 in-

put clock can support a 13.5 MHz data rate. This serial input

port is compatible with second generation digital filter chips

used in consumer audio products. These filters operate at over-

sampling rates of 23, 43, 83 and 163 sampling frequencies.

The critical specifications of THD+N and signal-to-noise ratio

are 100% tested for all devices.

The AD1851/AD1861 operates with ±5 V power supplies, mak-

ing it suitable for home use markets. The digital supply, V

, can

be separated from the analog supplies, V

and –V

, for reduced

digital crosstalk. Separate analog and digital ground pins are

also provided. Power dissipation is 100 mW typical.

The AD1851/AD1861 is available in either a 16-pin plastic DIP

or a 16-pin plastic SOIC package. Both packages incorporate

the industry standard pinout found on the AD1856 and

AD1860 PCM audio DACs. As a result, the AD1851/AD1861

is a drop-in replacement for designs where ±5 V supplies have

been used with the AD1856/AD1860. Operation is guaranteed

over the temperature range of –25°C to +70°C and over the

voltage supply range of ±4.75 V to ±5.25 V.

PRODUCT HIGHLIGHTS

l. AD1851 16-bit resolution provides 96 dB dynamic range.

AD1861 18-bit resolution provides 108 dB dynamic range.

2. No external components are required.

3. Operates with ±5 V supplies.

4. Space saving 16-pin SOIC and plastic DIP packages.

5. 100 mW power dissipation.

6. High input clock data rates and 1.5 µs settling time permits

23, 43, 83 and 163 oversampling.

7. ±3 V or ±1 mA output capability.

8. THD + Noise and SNR are 100% tested.

9. Pin-compatible with AD1856 & AD1860 PCM audio DACs.

Summary of content (12 pages)

PAGE 1
a FEATURES 110 dB SNR Fast Settling Permits 163 Oversampling 63 V Output Optional Trim Allows Super-Linear Performance 65 V Operation 16-Pin Plastic DIP and SOIC Packages Pin-Compatible with AD1856 & AD1860 Audio DACs 2s Complement, Serial Input APPLICATIONS High-End Compact Disc Players Digital Audio Amplifiers DAT Recorders and Players Synthesizers and Keyboards 16-Bit/18-Bit, 16 3 FS PCM Audio DACs AD1851/AD1861 FUNCTIONAL BLOCK DIAGRAM –VS 1 DGND 2 +VL 3 NC 4 CLK 5 LE 6 DATA 7 NC 8 LAT
PAGE 2
AD1851/AD1861–SPECIFICATIONS (T @ +258C and 65 V supplies, unless otherwise noted) A Min DIGITAL INPUTS VIH VIL IIH, VIH = VL IIL, VIL = 0.4 Typ 2.0 Max Units +VL 0.8 1.0 –10 V V µA µA ACCURACY Gain Error Midscale Output Voltage ±1 ± 10 % mV DRIFT (0°C to +70°C) Total Drift Bipolar Zero Drift ± 25 ±4 ppm of FSR/°C ppm of FSR/°C SETTLING TIME (To ± 0.0015% of FSR) Voltage Output 6 V Step 1 LSB Step Slew Rate Current Output 1 mA Step 10 Ω to 100 Ω Load 1 kΩ Load 1.5 1.
PAGE 3
AD1851/AD1861 AD1851 Min Typ Max Units 16 Bits 0.003 0.004 0.004 0.008 % % 0.009 0.009 0.016 0.040 % % 0.9 0.9 1.6 4.0 % % RESOLUTION TOTAL HARMONIC DISTORTION + NOISE 0 dB, 990.5 Hz AD1851N-J, R-J AD1851N, R –20 dB, 990.5 Hz AD1851N-J, R-J AD1851N, R –60 dB, 990.5 Hz AD1851N-J, R-J AD1851N, R D-RANGE* (With A-Weight Filter) –60 dB, 990.5 Hz AD1851N, R AD1851N-J, R-J 88 96 SIGNAL-TO-NOISE RATIO 107 MAXIMUM CLOCK INPUT FREQUENCY 12.
PAGE 4
AD1851/AD1861 ABSOLUTE MAXIMUM RATINGS* PIN DESCRIPTIONS VL to DGND . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 V to 6.50 V VS to AGND . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 V to 6.50 V –VS to AGND . . . . . . . . . . . . . . . . . . . . . . . . . –6.50 V to 0 V Digital Inputs to DGND . . . . . . . . . . . . . . . . . . . –0.3 V to VL AGND to DGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 0.3 V Short Circuit . . . . . . . . . . . . . . . . .
PAGE 5
AD1851/AD1861 TOTAL HARMONIC DISTORTION RF Total harmonic distortion plus noise (THD+N) is defined as the ratio of the square root of the sum of the squares of the values of the first 19 harmonics and noise to the value of the fundamental input frequency. It is usually expressed in percent (%). REFERENCE AUDIO OUTPUT THD+N is a measure of the magnitude and distribution of linearity error, differential linearity error, quantization error and noise.
PAGE 6
AD1851/AD1861 GROUNDING RECOMMENDATIONS However, three separate voltage supplies are not necessary for good circuit performance. For example, Figure 3 illustrates a system where only a single positive and a single negative supply are available. The AD1851/AD1861 has two ground pins, designated Analog and Digital ground. The analog ground pin is the “high quality” ground reference point for the device. The analog ground pin should be connected to the analog common point in the system.
PAGE 7
AD1851/AD1861 AD1851 DIGITAL CIRCUIT CONSIDERATIONS AD1851 Input Data AD1861 DIGITAL CIRCUIT CONSIDERATIONS AD1861 Input Data Data is transmitted to the AD1851 in a bit stream composed of 16-bit words with a serial, MSB first format. Three signals must be present to achieve proper operation. They are the Data, Clock and Latch Enable (LE) signals. Input data bits are clocked into the input register on the rising edge of the Clock signal. The LSB is clocked in on the 16th clock pulse.
PAGE 8
AD1851/AD1861 APPLICATIONS Figures 9 through 12 show connection diagrams for the AD1851 and AD1861 and the Yamaha YM3434 and the NPC SM5813AP/APT digital filter chips. CLK +5V CLK LATCH X1 ST 16/18 DLO DATA OUT AD1851 LEFT LOW OUTPUT PASS FILTER BCO YM3434 WCO DRO DATA LATCH CLK OUT AD1851 LOW PASS FILTER RIGHT OUTPUT Figure 9.
PAGE 9
AD1851/AD1861 +5V CLK LEFT OUTPUT CLK LATCH X1 COB OW20 DOL DATA OUT LOW PASS FILTER OUT LOW PASS FILTER AD1851 BCKO SM5813AP/APT WCKO DOR DATA OW18 LATCH CLK +5V AD1851 RIGHT OUTPUT Figure 11. AD1851 with NPC SM5813AP/APT Digital Filter +5V CLK LEFT OUTPUT CLK LATCH X1 COB OW20 DOL DATA OUT LOW PASS FILTER OUT LOW PASS FILTER AD1861 BCKO SM5813AP/APT WCKO OW18 DOR DATA LATCH CLK AD1861 Figure 12. AD1861 with NPC SM5813AP/APT Digital Filter REV.
PAGE 10
AD1851/AD1861 OTHER DIGITAL AUDIO COMPONENTS AVAILABLE FROM ANALOG DEVICES –VS 1 DGND 2 +VL 3 NC 4 CLK 5 LE 6 DATA 7 –VL 8 16-BIT LATCH 16-BIT DAC 16 +VS 15 TRIM SERIAL INPUT REGISTER AD1856 DGND 2 3 NC 4 CLK 5 11 SJ LE 6 10 RF DATA 7 –VL 8 13 IOUT 12 AGND CONTROL LOGIC 1 +VL 14 MSB ADJ IOUT –VS 9 VOUT 18-BIT LATCH 18-BIT DAC 16 +VS 15 TRIM SERIAL INPUT REGISTER 14 MSB ADJ 13 IOUT IOUT 12 AGND CONTROL LOGIC 11 SJ 10 RF AD1860 NC = NO CONNECT 9 VOUT NC
PAGE 11
AD1851/AD1861 OUTLINE DIMENSIONS Dimensions shown in inches and (mm). N (Plastic DIP) Package R (SOIC Surface Mount) Package 16 9 0.299 (7.60) 0.419 (10.65) 1 PIN 1 8 0.030 (0.75) 0.050 (1.27) 0.413 (10.50) 0.104 (2.650) 0.019 (0.49) REV. A 0.012 (0.30) –11– 0.013 (0.32) 0.042 (1.
PAGE 12
–12– PRINTED IN U.S.A.