Burr Brown PCM78P Datasheet

®

PCM78P

16-Bit Audio

ANALOG-TO-DIGITAL CONVERTER

FEATURES

● LOW COST/HIGH PERFORMANCE 16-BIT

AUDIO A/D CONVERTER

● FAST 5

(4

µs MAX CONVERSION TIME

µs typ)

● VERY LOW THD+N ( typ –88dB at FS;

max –82dB)

±3V INPUT RANGE

●

● TWO SERIAL OUTPUT MODES PROVIDE

VERSATILE INTERFACING

● COMPLETE WITH INTERNAL REFERENCE

AND CLOCK IN 28-PIN PLASTIC DIP

±5V TO ±15V SUPPLY RANGE (600mW

●

Power Dissipation)

DESCRIPTION

The PCM78P is a low-cost 16-bit analog-to-digital
converter which is specifically designed and tested for
dynamic applications. It features very fast, low
distortion performance (4µs/–88dB THD+N typical)
and is complete with internal clock and reference
circuitry. The PCM78P is packaged in a reliable, low­cost 28-pin plastic DIP and data output is available in
user-selectable serial output formats. The PCM78P is
ideal for digital audio tape (DAT) recorders. Many
similar applications such as digital signal processing
and telecom applications are equally well served by
the PCM78P.

The PCM78P uses a SAR technique. Analog and
digital portions are efficiently partitioned into a high­speed, bipolar section and a low-power CMOS
section. The PCM78P has been optimized for excel­lent dynamic performance and low cost.

APPLICATIONS

● DSP DATA ACQUISITION

● TEST INSTRUMENTATION

● SAMPLING KEYBOARD SYNTHESIZERS

● DIGITAL AUDIO TAPE

● BROADCAST AUDIO PROCESSING

● TELECOMMUNICATIONS

Audio Input

Convert 

Command

External Clock

16-bit D/A 

Converter

16-bit SAR +

Timing Control

Internal 

Clock

Circuit

Status

–
Comp
+

Serial Output 1
Serial Output 2
Clock Output

International Airport Industrial Park • Mailing Address: PO Box 11400 • Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd. • Tucson, AZ 85706

Tel: [phone] • Twx: 910-952-1111 • Cable: BBRCORP • Telex: 066-6491 • FAX: [phone] • Immediate Product Info: [phone]

©

1989 Burr-Brown Corporation PDS-989A Printed in U.S.A. October, 1993

SPECIFICATIONS

ELECTRICAL

At TC = +25°C, +V

PARAMETER CONDITIONS MIN TYP MAX UNITS
RESOLUTION 16 Bits
INPUT/OUTPUT
ANALOG INPUT

Input Range –3 +3 V
Input Impedance 1.5 kΩ

DIGITAL INPUT/OUTPUT

Logic Family TTL Compatible CMOS
Logic Level: V

Data Format Serial BOB or BTC
Convert Command Negative Edge
Pulse Width 25 50 ns

CONVERSION TIME 45 µs
DYNAMIC CHARACTERISTICS
SIGNAL-TO-NOISE RATIO (SNR)

f = 1kHz (0dB) BW = 20kHz 90 dB
f = 10kHz (0dB) BW = 100kHz 80 dB

TOTAL HARMONIC DISTORTION

f = 1kHz (0dB) BW = 20kHz –91 dB
f = 19kHz (0dB) BW = 20kHz –90 dB
f = 10kHz (0dB) BW = 100kHz –90 dB
f = 90kHz (0dB) BW = 100kHz –89 dB

TOTAL HARMONIC DISTORTION + NOISE

f = 1kHz (0dB) BW = 20kHz –88 –82 dB
f = 1kHz (–20dB) BW = 20kHz –74 –68 dB
f = 1kHz (–60dB) BW = 20kHz –34 dB
f = 19kHz (0dB) BW = 20kHz –87 dB
f = 10kHz (0dB) BW = 100kHz –82 dB
f = 90kHz (0dB) BW = 100kHz –81 dB

TRANSFER CHARACTERISTICS
ACCURACY

Gain Error ±2%
Bipolar Zero Error ±20 mV
Differential Linearity Error ±0.002 % of FSR
Integral Linearity Error ±0.003 % of FSR
Missing Codes None 14 Bits

DRIFT

Gain 0°C to +70°C ±25 ppm/°C
Bipolar Zero 0°C to +70°C ±4 ppm of FSR/°C

POWER SUPPLY SENSITIVITY

+V

CC

–V

CC

+V

DD

POWER SUPPLY REQUIREMENTS

Voltage Range: +V

Current: +V

Power Dissipation ±V

TEMPERATURE RANGE

Specification 0 +70 °C
Storage –50 +100 °C
Operating –25 +85 °C

= +5V, and ±VCC = ±12V, and one minute warm-up in convection environment, unless otherwise noted.

DD

IH

V

IL

V

OH

V

OL

(2)

(5)

(6)

CC

–V

CC

+V

DD
CC

–V

CC

+V

DD

IIH = +40µA +2 +5.5 V

IIL = –100µA 0 +0.8 V
IOH = 2TTL Loads +2.4 V
IOL = 2TTL Loads +0.4 V

CONV

CONV

= 4µs

= 4µs

= 4µs

(3)

fS = 200kHz/T

fS = 200kHz/T

fS = 200kHz/T

CONV

+4.75 +15.6 V
–4.75 –15.6 V

+4.75 +5.25 V
+VCC = +12V +15 mA
–VCC = –12V –21 mA

+VDD = +5V +7 mA

= ±12V 575 mW

CC

PCM78P

(1)

±0.008 %FSR/%V
±0.003 %FSR/%V
±0.003 %FSR/%V

(4)

(7)

(8)

CC
CC
DD

NOTES: (1) When convert command is high, converter is in a halt/reset mode. Actual conversion begins on negative edge. See detailed text on timing for convert
command description when using external clock. (2) Ratio of Noise rms/Signal rms. (3) f = input frequency; f
combination); BW = bandwidth of output (based on FFT or actual analog reconstruction using a 20kHz low-pass filter). (4) Referred to input signal level. (5) Ratio

= sample frequency (PCM78P and SHC702 in

S

of Distortion rms/Signal rms. (6) Ratio of Distortion rms + Noise rms/Signal rms. (7) FSR: Full-Scale Range = 6Vp-p. (8) Typically no missing Codes at 14-bit
resolution.

®

PCM78 2

PIN ASSIGNMENTS

PIN NAME I/O DESCRIPTION

1 Analog In I Analog Signal Input (1.5kΩ impedance).

2–V

CC

3 MSB Adjust I Internal adjustment point to allow adjustment of MSB major carry.
4+V

DD

5 No Connection — No internal connection.
6 Comparator Common I Comparator common connection. Connect to ground.

7 MSB O Parallel output of bit 1 (MSB) inverted.
8 BTC/BOB Select I Two’s complement (open) or straight binary (grounded) data output format selection.
9 Status O Output signal held high until conversion is complete.

10 Clock Out O Internal clock output generated from RC network on pins 11 and 12 (also present when external clock is used lagging

11 R

1C1

12 R

2C2

13 S

OUT2

14 +V

DD

15 S

OUT1

16 External Clock I External clock input point (internal clock must be disabled).
17 Int/Ext Clock Select I Selects either internal or external clock mode (low = internal; open = external).
18 Short Cycle I Terminates conversion at less than 16 bits (open for 16-bit mode). See text for details.
19 Convert Command I Starts conversion process (can optionally be generated internally).
20 S

21 S
22 Digital Common I Digital grounding pin.
23 +V
24 V
25 Reference Decouple I Reference decoupling point.

Latch I Latches previous conversion result for readout (must be issued with the S

OUT2

Clock I Used to read out internally latched data from previous conversion.

OUT2

CC

POT

26 Analog Common I Analog grounding pin.
27 Reference Out O 2V reference out. Should not be used except as shown in connection diagram.
28 Speed Up I Connection point for a capacitor to speed reference settling. See text for details.

NOTE: Analog and digital commons are connected internally.

I Analog power supply (–5V to –15V).

I Power connection for comparator (+5V).

external clock by ~24ns and same duty cycle).
I RC connection point used to generate internal clock. Sets clock high time. See text for details.
I RC connection point used to generate internal clock. Sets clock low time. See text for details.

O Internal shift register containing the previous conversion result. (Alternate latched data output mode).

I Power connection for +5V logic supply.

O Primary real-time data output synchronized to clock out.

clock to initiate latch and an internal convert

command).

OUT2

I Analog supply connection (+5V to +15V).

O Voltage output (~2.5V) for optional adjustment of MSB transition.

INPUT/OUTPUT RELATIONSHIPS

DIGITAL OUTPUT

ANALOG INPUT CONDITION BTC BOB

+2.999908V + Full Scale 7FFF Hex FFFF Hex

–3.000000V –Full Scale 8000 Hex 0000 Hex

0.000000V Bipolar Zero 0000 Hex 8000 Hex

–0.000092V Zero-1 LSB FFFF Hex 7FFF Hex

PACKAGE INFORMATION

MODEL PACKAGE NUMBER

PACKAGE DRAWING

PCM78P 28-Pin Plastic DIP 215

NOTE: (1) For detailed drawing and dimension table, please see end of data
sheet, or Appendix D of Burr-Brown IC Data Book.

(1)

ABSOLUTE MAXIMUM RATINGS

+V

to Analog Common .........................................................0 to +16.5V

CC

–V

to Analog Common .........................................................0 to –16.5V

CC

–V

to Analog Common ..............................................................0 to +7V

DD

Analog Common to Digital Common................................................. ±0.5V

Logic Inputs to Digital Common ................................. –0.3V to V

Analog Inputs to Analog Common .................................................. ±16.5V

Lead Temperature (soldering, 10s)................................................ +300°C

Stresses above these ratings may permanently damage the device.

DD

+ 0.5V

The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes
no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change
without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant
any BURR-BROWN product for use in life support devices and/or systems.

PCM783

®

TYPICAL PERFORMANCE CURVES

At TA = +25°C, VCC = ±15V, unless otherwise noted.

10mV

9mV
8mV

7mV
6mV
5mV
4mV

BPZ Error (mV)

3mV
2mV
1mV

0

–25 0 25 70 125

BPZ ERROR vs TEMPERATURE

Temperature (°C)

BIPOLAR GAIN ERROR as % FSR

25°C; N = 33 UNITS

18
16
14
12
10

8
6

Number of Units

4
2
0

–0.35 –0.45 –0.60

–0.40 –0.55

–0.50

% FSR

0.012

0.010

–V

CC

0.008

0.006

0.004

PSRR at +FS INPUT

0.002

% / %

–0.002

0

+V

CC

–0.004
–0.006

V

DD

–0.008
–0.010

–25 0 25 70 125

Temperature (°C)

V vs TEMP

2.002

REF

2.000

1.998

1.996

REF

1.994

V (V)

1.992

1.99

1.988
–25 0 25 70 125

Temperature (°C)

0.012

PSRR at –FS INPUT

0.01
–V

0.008

0.006

% / %

CC

+V

CC

0.004

0.002

V

DD

0

–25 0 25 70 125

Temperature (°C)

I vs SUPPLY VOLTAGE

–V

SS

CC

21

20

19

18

17

Current (mA)

16

15

+V

CC

14

41016

6 8 12 14

Supply Voltage (V)

®

PCM78 4

DIFFERENTIAL NONLINEARITY

at 25°C

1.40

0.80

0.60

0.00
1

1.20

LSB

0.20

Major Carry Bit Number

1.00

0.40

2345678910111213141516

DIFFERENTIAL NONLINEARITY

at 0°C

1.40

0.80

0.60

0.00
1

1.20

LSB

0.20

Major Carry Bit Number

1.00

0.40

2345678910111213141516

DIFFERENTIAL NONLINEARITY

at –25°C

1.40

1.00

0.00
1

LSB

Major Carry Bit Number

1.20

0.80

2345678910111213141516

0.60

0.40

0.20

TYPICAL PERFORMANCE CURVES (CONT)

At TA = +25°C, VCC = ±15V, unless otherwise noted.

INTEGRAL NONLINEARITY

at –25°C

Major Carry Bit Number

LSB

7.00

6.00

5.00

4.00

3.00

2.00

1.00

0.00

–1.00

2345678910111213141516

1

LSB

LSB

5.00

4.00

3.00

2.00

1.00

0.00

–1.00

–2.00

5.00

4.00

3.00

2.00

1.00

INTEGRAL NONLINEARITY

2345678910111213141516

1

INTEGRAL NONLINEARITY

at 0°C

Major Carry Bit Number

at 25°C

0.00

–1.00

–2.00

2345678910111213141516

1

Major Carry Bit Number

®

PCM785