Datasheet PCM63P, PCM63P-J, PCM63P-K Datasheet (Burr Brown)

®

PCM63P

PCM63P

DEMO BOARD

AVAILABLE

See Appendix A

Colinear

™

20-Bit Monolithic Audio

DIGITAL-TO-ANALOG CONVERTER

FEATURES

●

COLINEAR

● NEAR-IDEAL LOW LEVEL OPERATION

● GLITCH-FREE OUTPUT

● ULTRA LOW –96dB max THD+N

(Without External Adjustment)

● 116dB SNR min (A-Weight Method)

● INDUSTRY STD SERIAL INPUT FORMAT

● FAST (200ns) CURRENT OUTPUT

(±2mA; ±2% max)

● CAPABLE OF 16x OVERSAMPLING

● COMPLETE WITH REFERENCE

Clock

Latch Enable

Data

20-BIT AUDIO DAC

+5V

Analog

213

18

Input Shift

20

21

Register

and

Control

Logic

+5V

Analog

Digital

Upper DAC

Positive

Data Latches

Lower DAC

Negative

Data Latches

–5V

28 11

Digital

–5V

DESCRIPTION

The PCM63P is a precision 20-bit digital-to-analog
converter with ultra-low distortion (–96dB max with a
full scale output; PCM63P-K). Incorporated into the
PCM63P is a unique
architecture that eliminates unwanted glitches and
other nonlinearities around bipolar zero. The PCM63P
also features a very low noise (116dB max SNR;
A-weighted method) and fast settling current output
(200ns typ, 2mA step) which is capable of 16-times
oversampling rates.

Applications include very low distortion frequency
synthesis and high-end consumer and professional
digital audio applications.

Upper

Lower

B2 Adj

B2 Adj

23 24

19-Bit
Upper

DAC

19-Bit

Lower

DAC

PCM63P

Colinear

Colinear

20-Bit DAC

dual-DAC per channel

9

R

FEEDBACK

10

R

FEEDBACK

6

I

OUT

Buried

Zener

Reference

31

Reference

Decouple

Colinear

™, Burr-Brown Corp.

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

Internet: http://www.burr-brown.com/ • FAXLine: [phone] (US/Canada Only) • Cable: BBRCORP • Telex: 066-6491 • FAX: [phone] • Immediate Product Info: [phone]

© 1990 Burr-Brown Corporation PDS-1083F Printed in U.S.A. January, 1998

Servo

Amp

Servo

Decouple

Ref

Amp

25 7 12

Potentiometer

Voltage

Analog

Common

1

Digital

Common

54Bipolar Offset Current

Offset Decouple

®

PCM63P

SPECIFICATIONS

ELECTRICAL

All specifications at 25°C and ±VA and ±VD = ±5V, unless otherwise noted.

PCM63P, PCM63P-J, PCM63P-K

PARAMETER CONDITIONS MIN TYP MAX UNITS
RESOLUTION 20 Bits
DYNAMIC RANGE, ΤΗD+Ν at –60dB Referred to Full Scale

PCM63P 96 100 dB
PCM63P-J 100 104 dB
PCM63P-K 104 108 dB

DIGITAL INPUT

Logic Family TTL/CMOS Compatible
Logic Level: V

Data Format Serial, MSB First, BTC

IH

V

IL

I

IH

I

IL

VIH = +2.7V +1 µA
VIL = +0.4V –50 µA

Input Clock Frequency 12.5 25 MHz

(2)

TOTAL HARMONIC DISTORTION + N

PCM63P

f = 991Hz (0dB)

(3)

f = 991Hz (–20dB) f
f = 991Hz (–60dB) f

PCM63P-J

f = 991Hz (0dB) f
f = 991Hz (–20dB) f
f = 991Hz (–60dB) f

PCM63P-K

f = 991Hz (0dB) f
f = 991Hz (–20dB) f
f = 991Hz (–60dB) f

, Without Adjustments

fS = 352.8kHz

= 352.8kHz –80 –74 dB

S

= 352.8kHz –40 –36 dB

S

= 352.8kHz –96 –92 dB

S

= 352.8kHz –82 –76 dB

S

= 352.8kHz –44 –40 dB

S

= 352.8kHz –100 –96 dB

S

= 352.8kHz –88 –82 dB

S

= 352.8kHz –48 –44 dB

S

(4)

ACCURACY

Level Linearity at –90dB Signal Level ±0.3 ±1dB
Gain Error ±1 ± 2%
Bipolar Zero Error

(5)

Gain Drift 0°C to 70°C 25 ppm/°C
Bipolar Zero Drift 0°C to 70°C 4 ppm of FSR/°C
Warm-up Time 1 Minute

IDLE CHANNEL SNR

(6)

20Hz to 20kHz at BPZ

(7)

POWER SUPPLY REJECTION +86 dB
ANALOG OUTPUT

Output Range ±2.00 mA
Output Impedance 670 Ω
Internal R

FEEDBACK

Settling Time 2mA Step 200 ns
Glitch Energy No Glitch Around Zero

POWER SUPPLY REQUIREMENTS

, ±VD Supply Voltage Range ±4.50 ± 5 ±5.50 V

±V

A

, +ID Combined Supply Current +VA, +VD = +5V 10 15 mA

+I

A

, –ID Combined Supply Current –VA, –VD = –5V –35 –45 mA

–I

A

Power Dissipation ±V

, ±VD = ±5V 225 300 mW

A

TEMPERATURE RANGE

Specification 0 +70 °C
Operating –40 +85 °C
Storage –60 +100 °C

NOTES: (1) Binary Two’s Complement coding. (2) Ratio of (Distortion
converter sample frequency (8 x 44.1kHz; 8x oversampling). (5) Offset error at bipolar zero. (6) Measured using an OPA27 and 1.5kΩ feedback and an A-weighted

RMS

+ Noise

filter. (7) Bipolar Zero.

+2.4 +V

0 0.8 V

D

(1)

–92 –88 dB

±12 µA

+116 +120 dB

1.5 kΩ

RMS

) / Signal

. (3) D/A converter output frequency (signal level). (4) D/A

RMS

V

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.

®

PCM63P

2

PIN ASSIGNMENTS

PIN DESCRIPTION MNEMONIC

P1 Servo Amp Decoupling Capacitor CAP
P2 +5V Analog Supply Voltage +V
P3 Reference Decoupling Capacitor CAP

A

P4 Offset Decoupling Capacitor CAP
P5 Bipolar Offset Current Output (+2mA) BPO
P6 DAC Current Output (0 to –4mA) I
P7 Analog Common Connection ACOM

OUT

P8 No Connection NC
P9 Feedback Resistor Connection (1.5kΩ)RF
P10 Feedback Resistor Connection (1.5kΩ)RF
P11 –5V Digital Supply Voltage –V
P12 Digital Common Connection DCOM
P13 +5V Digital Voltage Supply +V
P14 No Connection NC

1
2

D

D

P15 No Connection NC
P16 No Connection NC
P17 No Connection NC
P18 DAC Data Clock Input CLK
P19 No Connection NC
P20 DAC Data Latch Enable LE
P21 DAC Data Input DATA
P22 No Connection NC
P23 Optional Upper DAC Bit-2 Adjust (–4.29V)* UB2 Adj
P24 Optional Lower DAC Bit-2 Adjust (–4.29V)* LB2 Adj
P25 Bit Adjust Reference Voltage Tap (–3.52V)* V
P26 No Connection NC

POT

P27 No Connection NC
P28 –5V Analog Supply Voltage –V

A

*Nominal voltages at these nodes assuming ±VA; ±VD = ±5V.

ORDERING INFORMATION

PRODUCT PACKAGE RANGE AT 0dB

PCM63P 28-Pin Plastic DIP 0°C to +70°C –88dB
PCM63P-J 28-Pin Plastic DIP 0°C to +70°C –92dB
PCM63P-K 28-Pin Plastic DIP 0°C to +70°C –96dB

TEMPERATURE MAX THD+N,

ABSOLUTE MAXIMUM RATINGS

+VA, +VD to ACOM/DCOM........................................................0V to +8V

, –VD to ACOM/DCOM ........................................................ 0V to –8V

–V

A

, –VD to +VA, +VD............................................................. 0V to +16V

–V

A

ACOM to DCOM ............................................................................... ±0.5V

Digital Inputs (pins 18, 20, 21) to DCOM ............................... –1V to +V

Power Dissipation .......................................................................... 500mW

D

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

Max Junction Temperature .............................................................. 165°C

θ

Thermal Resistance,

...............................................................70°C/W

JA

NOTE: Stresses above those listed under “Absolute Maximum Ratings”
may cause permanent damage to the device. Exposure to absolute
maximum conditions for extended periods may affect device reliability.

PACKAGE INFORMATION

PRODUCT PACKAGE NUMBER

PACKAGE DRAWING

PCM63P 28-Pin Plastic DIP 215
PCM63P-J 28-Pin Plastic DIP 215
PCM63P-K 28-Pin Plastic DIP 215

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

(1)

®

3

PCM63P

TYPICAL PERFORMANCE CURVES

All specifications at 25°C and ±VA and ±VD = ±5.0V, unless otherwise noted.

–40

–60

–80

THD+N (dB)

–100

–120

20 100 1k 10k

THD+N vs FREQUENCY

–60dB

–40dB

–20dB

0dB

Output Frequency (Hz)

16-BIT LEVEL LINEARITY

8
6
4
2

0
–2
–4

Deviation from Ideal Level (dB)

–6
–8

–120

(Dithered Fade to Noise)

–110 –100 –90 –80 –70 –60

Output Signal Level (dB)

1.5

1

0.5

0

–0.5

Output Voltage (mV)

–1

–1.5

200

100

0

Output Level (µV)

–100

16-BIT MONOTONICITY

8.83ms/div

–90dB SIGNAL

(10Hz to 20kHz Bandwidth)

FPO

–90dB SIGNAL SPECTRUM

–80

–100

–120

Power Spectrum (dB)

–140

–160

0 4k 8k 12k 16k 20k

40

20

0

Output Level (µV)

–20

(100Hz Bandwidth)

FPO

Frequency (Hz)

–110dB SIGNAL

(10Hz to 20kHz Bandwidth)

FPO

–200

0 400 800 1200 1600 2000

Time (µs)

®

PCM63P

–40

0 400 800 1200 1600 2000

Time (µs)



4

THEORY OF OPERATION

DUAL-DAC

Digital audio systems have traditionally used laser-trimmed,
current-source DACs in order to achieve sufficient accuracy.
However even the best of these suffer from potential low­level nonlinearity due to errors at the major carry bipolar
zero transition. More recently, DACs employing a different
architecture which utilizes noise shaping techniques and
very high oversampling frequencies, have been introduced
(“Bitstream”, “MASH”, or 1-bit DACs). These DACs over­come the low level linearity problem, but only at the expense
of signal-to-noise performance, and often to the detriment of
channel separation and intermodulation distortion if the
succeeding circuitry is not carefully designed.

The PCM63 is a new solution to the problem. It combines all
the advantages of a conventional DAC (excellent full scale
performance, high signal-to-noise ratio and ease of use) with
superior low-level performance. Two DACs are combined
in a complementary arrangement to produce an extremely
linear output. The two DACs share a common reference and
a common R-2R ladder to ensure perfect tracking under all
conditions. By interleaving the individual bits of each DAC
and employing precise laser trimming of resistors, the highly
accurate match required between DACs is achieved.

This new, complementary linear or dual-DAC
approach, which steps away from zero with small steps in
both directions, avoids any glitching or “large” linearity
errors and provides an absolute current output. The low level
performance of the PCM63P is such that real 20-bit resolu­tion can be realized, especially around the critical bipolar
zero point.

Table I shows the conversion made by the internal logic of
the PCM63P from binary two’s complement (BTC). Also,
the resulting internal codes to the upper and lower DACs
(see front page block diagram) are listed. Notice that only
the LSB portions of either internal DAC are changing
around bipolar zero. This accounts for the superlative per­formance of the PCM63P in this area of operation.

COLINEAR

ARCHITECTURE

Colinear

DISCUSSION OF SPECIFICATIONS

DYNAMIC SPECIFICATIONS
Total Harmonic Distortion + Noise

The key specification for the PCM63P is total harmonic
distortion plus noise (THD+N). Digital data words are read
into the PCM63P at eight times the standard compact disk
audio sampling frequency of 44.1kHz (352.8kHz) so that a
sine wave output of 991Hz is realized. For production
testing, the output of the DAC goes to an I to V converter,
then to a programmable gain amplifier to provide gain at
lower signal output test levels, and then through a 40kHz
low pass filter before being fed into an analog type distortion
analyzer. Figure 1 shows a block diagram of the production
THD+N test setup.

For the audio bandwidth, THD+N of the PCM63P is essen­tially flat for all frequencies. The typical performance curve,
“THD+N vs Frequency,” shows four different output signal
levels: 0dB, –20dB, –40dB, and –60dB. The test signals are
derived from a special compact test disk (the CBS CD-1). It
is interesting to note that the –20dB signal falls only about
10dB below the full scale signal instead of the expected
20dB. This is primarily due to the superior low-level signal
performance of the dual-DAC
PCM63P.

In terms of signal measurement, THD+N is the ratio of
Distortion

RMS

+ Noise

RMS

the PCM63P, THD+N is 100% tested at all three specified
output levels using the test setup shown in Figure 1. It is
significant to note that this test setup does not include any
output deglitching circuitry. All specifications are achieved
without the use of external deglitchers.

Dynamic Range

Dynamic range in audio converters is specified as the measure
of THD+N at an effective output signal level of –60dB
referred to 0dB. Resolution is commonly used as a theoretical
measure of dynamic range, but it does not take into account
the effects of distortion and noise at low signal levels. The

Colinear

/ Signal

architecture of the

expressed in dB. For

RMS

ANALOG OUTPUT (20-bit Binary Two’s Complement) (19-bit Straight Binary) (19-bit Straight Binary)

+Full Scale 011...111 111...111 + 1LSB* 111...111
+Full Scale – 1LSB 011...110 111...111 + 1LSB* 111...110
Bipolar Zero + 2LSB 000...010 111...111 + 1LSB* 000...010
Bipolar Zero + 1LSB 000...001 111...111 + 1LSB* 000...001
Bipolar Zero 000...000 111...111 + 1LSB* 000...000
Bipolar Zero – 1LSB 111...111 111...111 000...000
Bipolar Zero – 2LSB 111...110 111...110 000...000
–Full Scale + 1LSB 100...001 000...001 000...000
–Full Scale 100...000 000...000 000...000

*The extra weight of 1LSB is added at this point to make the transfer function symmetrical around bipolar zero.

TABLE I. Binary Two’s Complement to

INPUT CODE LOWER DAC CODE UPPER DAC CODE

Colinear

Conversion Chart.

5

PCM63P

®

Use 400Hz High-Pass

Filter and 30kHz

Low-Pass Filter

Meter Settings

Distortion

Analyzer

(Shiba Soku Model

725 or Equivalent)

Programmable

Gain Amp

0dB to 60dB

Low-Pass

Filter

40kHz 3rd Order

GIC Type

Binary 

Counter

Digital Code

(EPROM)

Timing

Logic

FIGURE 1. Production THD+N Test Setup.

Colinear

architecture of the PCM63P, with its ideal
performance around bipolar zero, provides a more usable
dynamic range, even using the strict audio definition, than
any previously available D/A converter.

Level Linearity

Deviation from ideal versus actual signal level is sometimes
called “level linearity” in digital audio converter testing. See
the “–90dB Signal Spectrum” plot in the Typical Perfor­mance Curves section for the power spectrum of a PCM63P
at a –90dB output level. (The “–90dB Signal” plot shows the
actual –90dB output of the DAC). The deviation from ideal
for PCM63P at this signal level is typically less than ±0.3dB.
For the “–110dB Signal” plot in the Typical Performance
Curves section, true 20-bit digital code is used to generate a
–110dB output signal. This type of performance is possible
only with the low-noise, near-theoretical performance around
bipolar zero of the PCM63P’s

Colinear

DAC circuitry.

A commonly tested digital audio parameter is the amount of
deviation from ideal of a 1kHz signal when its amplitude is
decreased from –60dB to –120dB. A digitally dithered input
signal is applied to reach effective output levels of –120dB
using only the available 16-bit code from a special compact
disk test input. See the “16-Bit Level Linearity” plot in the
Typical Performance Curves section for the results of a
PCM63P tested using this 16-bit dithered fade-to-noise
signal. Note the very small deviation from ideal as the signal
goes from –60dB to –100dB.

DC SPECIFICATIONS
Idle Channel SNR

Another appropriate specification for a digital audio con­verter is idle channel signal-to-noise ratio (idle channel
SNR). This is the ratio of the noise on the DAC output at
bipolar zero in relation to the full scale range of the DAC. To

Parallel-to-Serial

Conversion

Clock

Sampling Rate = 44.1kHz x 8 (352.8kHz)

Output Frequency = 991Hz

DUT

(PCM63P)

Latch Enable

make this measurement, the digital input is continuously fed
the code for bipolar zero while the output of the DAC is
band-limited from 20Hz to 20kHz and an A-weighted filter
is applied. The idle channel SNR for the PCM63P is typi­cally greater than 120dB, making it ideal for low-noise
applications.

Monotonicity

Because of the unique dual-DAC

Colinear

the PCM63P, increasing values of digital input will always
result in increasing values of DAC output as the signal
moves away from bipolar zero in one-LSB steps (in either
direction). The “16-Bit Monotonicity” plot in the Typical
Performance Curves section was generated using 16-bit
digital code from a test compact disk. The test starts with 10
periods of bipolar zero. Next are 10 periods of alternating
1LSBs above and below zero, and then 10 periods of
alternating 2LSBs above and below zero, and so on until
10LSBs above and below zero are reached. The signal
pattern then begins again at bipolar zero.

With PCM63P, the low-noise steps are clearly defined and
increase in near-perfect proportion. This performance is
achieved without any external adjustments. By contrast,
sigma-delta (“Bitstream”, “MASH”, or 1-bit DAC) architec­tures are too noisy to even see the first 3 or 4 bits change (at
16 bits), other than by a change in the noise level.

Absolute Linearity

Even though absolute integral and differential linearity specs
are not given for the PCM63P, the extremely low THD+N
performance is typically indicative of 16-bit to 17-bit inte­gral linearity in the DAC, depending on the grade specified.
The relationship between THD+N and linearity, however, is
not such that an absolute linearity specification for every
individual output code can be guaranteed.

I to V

Converter

OPA627

architecture of

®

PCM63P

6

Offset, Gain, And Temperature Drift

Although the PCM63P is primarily meant for use in dy­namic applications, specifications are also given for more
traditional DC parameters such as gain error, bipolar zero
offset error, and temperature gain and offset drift.

DIGITAL INPUT
Timing Considerations

The PCM63P accepts TTL compatible logic input levels.
Noise immunity is enhanced by the use of differential
current mode logic input architectures on all input signal
lines. The data format of the PCM63P is binary two’s
complement (BTC) with the most significant bit (MSB)
being first in the serial input bit stream. Table II describes
the exact relationship of input data to voltage output coding.
Any number of bits can precede the 20 bits to be loaded,
since only the last 20 will be transferred to the parallel DAC
register after LE (P20, Latch Enable) has gone low.

All DAC serial input data (P21, DATA) bit transfers are
triggered on positive clock (P18, CLK) edges. The serial-to­parallel data transfer to the DAC occurs on the falling edge
of Latch Enable (P20, LE). The change in the output of the
DAC coincides with the falling edge of Latch Enable (P20,
LE). Refer to Figure 2 for graphical relationships of these
signals.

Maximum Clock Rate

A typical clock rate of 16.9MHz for the PCM63P is derived
by multiplying the standard audio sample rate of 44.1kHz by

sixteen times (16x oversampling) the standard audio word
bit length of 24 bits (44.1kHz x 16 x 24 = 16.9MHz). Note
that this clock rate accommodates a 24-bit word length, even
though only 20 bits are actually being used. The maximum
clock rate of 25MHz is guaranteed, but is not 100% final
tested. The setup and hold timing relationships are shown in
Figure 3.

“Stopped Clock” Operation

The PCM63P is normally operated with a continuous clock
input signal. If the clock is to be stopped between input data
words, the last 20 bits shifted in are not actually shifted from
the serial register to the latched parallel DAC register until
Latch Enable (LE, P20) goes low. Latch Enable must remain
low until after the first clock cycle of the next data word
to insure proper DAC operation. In any case, the setup and
hold times for Data and LE must be observed as shown in
Figure 3.

Data

Input

Clock

Input

Latch

Enable

>20ns

LSB

>10ns

>10ns

>15ns >15ns

>33ns

>One Clock Cycle

MSB

>1ns

>10ns

>One Clock Cycle

FIGURE 3. Setup and Hold Timing Diagram.

DIGITAL INPUT ANALOG OUTPUT CURRENT OUTPUT (With External Op Amp)

1,048,576LSBs Full Scale Range 4.00000000mA 6.00000000V
1LSB NA 3.81469727nA 5.72204590µV
7FFFF

HEX

00000

HEX

FFFFF

HEX

80000

HEX

+Full Scale –1.99999619mA +2.99999428V

Bipolar Zero 0.00000000mA 0.00000000V

Bipolar Zero – 1LSB +0.00000381mA –0.00000572V

–Full Scale +2.00000000mA –3.00000000V

VOLTAGE OUTPUT

TABLE II. Digital Input/Output Relationships.

P18 (Clock)

P21 (Data)

MSB

P20 (Latch Enable)

P6 (I )

OUT

NOTES: (1) If clock is stopped between input of 20-bit data words, Latch Enable (LE) must remain low until after the first clock cycle of the next 20-bit data
word stream. (2) Data format is binary two’s complement (BTC). Individual data bits are clocked in on the corresponding positive clock edge. (3) Latch Enable
(LE) must remain low at least one clock cycle after going negative. (4) Latch Enable (LE) must be high for at least one clock cycle before going negative.
(5) I

changes on negative going edge of Latch Enable (LE).

OUT

3 1213141516171819204

1

2

1

LSB

FIGURE 2. Timing Diagram.

7

PCM63P

®

INSTALLATION

POWER SUPPLIES

Refer to Figure 4 for proper connection of the PCM63P in
the voltage-out mode using the internal feedback resistor.
The feedback resistor connections (P9 and P10) should be
left open if not used. The PCM63P only requires a ±5V
supply. Both positive supplies should be tied together at a
single point. Similarly, both negative supplies should be
connected together. No real advantage is gained by using
separate analog and digital supplies. It is more important that
both these supplies be as “clean” as possible to reduce
coupling of supply noise to the output. Power supply decou­pling capacitors should be used at each supply pin to
maximize power supply rejection, as shown in Figure 4,
regardless of how good the supplies are. Both commons
should be connected to an analog ground plane as close to
the PCM63P as possible.

desired. Use of the MSB adjustments will only affect larger
dynamic signals (between 0dB and –6dB). This improve­ment comes from bettering the gain match between the
upper and lower DACs at these signal levels. The change is
realized by small adjustments in the bit-2 weights of each
DAC. Great care should be taken, however, as improper
adjustment will easily result in degraded performance.

In theory, the adjustments would seem very simple to
perform, but in practice they are actually quite complex. The
first step in the theoretical procedure would involve making
each bit-2 weight ideal in relation to its code minus one
value (adjusting each potentiometer for zero differential
nonlinearity error at the bit-2 major carries). This would be
the starting point of each 100kΩ potentiometer for the next
adjustment. Then, each potentiometer would be adjusted
equally, in opposite directions, to achieve the lowest full­scale THD+N possible (reversing the direction of rotation

FILTER CAPACITOR REQUIREMENTS

As shown in Figure 4, various size decoupling capacitors
can be used, with no special tolerances being required. The
size of the offset decoupling capacitor is not critical either,
with larger values (up to 100µF) giving slightly better SNR
readings. All capacitors should be as close to the appropriate
pins of the PCM63P as possible to reduce noise pickup from
surrounding circuitry.

MSB ADJUSTMENT CIRCUITRY

Near optimum performance can be maintained at all signal
levels without using the optional MSB adjust circuitry of the
PCM63P shown in Figure 5. Adjustability is provided for
those cases where slightly better full-scale THD+N is

–5V

+5V

1µF

±3V

1/2

OPA2604

1µF

1µF

28

–V 

A

V 

POT

LB2 Adj

UB2 Adj

25

24

23

0.1µF

100kΩ

330kΩ

330kΩ

0.1µF

FIGURE 5. Optional Bit-2 Adjustment Circuitry.

0.1µF

0.1µF

4.7µF

PCM63P

1

CAP

2

+V

A

3

CAP

4

+

CAP

5

BPO

6

I

OUT

7

ACOM

8

NC

9

RF

1

10

RF

2

11

–V

D

12

DCOM



13

+V

D

14

NC

–V 

NC
NC

V 

POT

LB2 Adj

UB2 Adj

NC

DATA

NC

CLK

NC
NC
NC

A

LE

1µF

28
27
26
25

0.1µF

24
23

0.1µF

22
21
20
19
18
17
16
15

100kΩ

FIGURE 4. Connection Diagram.

®

PCM63P

8

for both if no immediate improvement were noted). This
procedure would require the generation of the digital bit-2
major carry code to the input of the PCM63P and a DVM or
oscilloscope capable of reading the output voltage for a one
LSB step (5.72µV) in addition to a distortion analyzer.

A more practical approach would be to forego the minor
correction for the bit-2 major carry adjustment and only
adjust for upper and lower DAC gain matching. The prob­lem is that just by connecting the MSB circuitry to the
PCM63P, the odds are that the upper and lower bit-2 weights
would be greatly changed from their unadjusted states and
thereby adversely affect the desired gain adjustment. Just
centering the 100kΩ potentiometers would not necessarily
provide the correct starting point. To guarantee that each
100kΩ potentiometer would be set to the correct starting or
null point (no current into or out of the MSB adjust pins), the
voltage drop across each corresponding 330kΩ resistor would
have to measure 0V. A voltage drop of ±1.25mV across
either 330kΩ resistor would correspond to a ±1LSB change
in the null point from its unadjusted state (1LSB in current
or 3.81nA x 330kΩ = 1.26mV). Once these starting points
for each potentiometer had been set, each potentiometer
would then be adjusted equally, in opposite directions, to
achieve the lowest full-scale THD+N possible. If no imme­diate improvement were noted, the direction of rotation for
both potentiometers would be reversed. One direction of
potentiometer counter-rotations would only make the gain
mismatch and resulting THD+N worse, while the opposite
would gradually improve and then worsen the THD+N after
passing through a no mismatch point. The determination of

the correct starting direction would be arbitrary. This proce­dure still requires a good DVM in addition to a distortion
analyzer.

Each user will have to determine if a small improvement in
full-scale THD+N for their application is worth the expense
of performing a proper MSB adjustment.

APPLICATIONS

The most common application for the PCM63P is in high­performance and professional digital audio playback, such
as in CD and DAT players. The circuit in Figure 6 shows the
PCM63P in a typical combination with a digital interface
format receiver chip (Yamaha YM3623), an 8x interpolating
digital filter (Burr-Brown DF1700P), and two third-order
low-pass anti-imaging filters (implemented using Burr-Brown
OPA2604APs).

Using an 8x digital filter increases the number of samples to
the DAC by a factor of 8, thereby reducing the need for a
higher order reconstruction or anti-imaging analog filter on
the DAC output. An analog filter can now be constructed
using a simple phase-linear GIC (generalized immittance
converter) architecture. Excellent sonic performance is
achieved using a digital filter in the design, while reducing
overall circuit complexity at the same time.

Because of its superior low-level performance, the PCM63P
is also ideally suited for other high-performance applications
such as direct digital synthesis (DDS).

®

9

PCM63P

OUT

±3VVRight

OUT

±3VVLeft

+5V

4.7µF

1

+

8

+

4.7µF

1

4

A

3

2

–5V

+5V

1000pF

1

+

4.7µF
8

+5V

1.33kΩ

7.23kΩ

3.92kΩ

+

2

A

3

0.1µF

4.7µF

4

2

7.23kΩ

–5V

1000pF

1000pF

6

3.47kΩ

5

2

A

7

7

1

A

5

6

1µF

0.1µF

24

23

1056

9

+5V

0.1µF

1µF 1µF

3132

20-Bit D/A

7

Converter

12

DATA

21

CLK

18

LE

4

20

PCM63P

Burr-Brown

4.7µF

12811

0.1µF

1µF

+

+5V

4.7µF

4.7µF

17 223

8X Interpolation

+

23

DOR

Digital Filter

6

26

BCO

2

25

WCK

28

24

DOL

1

DF1700P

Burr-Brown

104
8

14 2116

100pF

4.7µF

–5V

1

+

8

+

3

A

3

4.7µF

4

2

–5V

1000pF

1

A

3

20-Bit D/A

7

4

4

2

7.23kΩ

0.1µF

24

Converter

12

+

4.7µF

–5V

1000pF

1000pF

6

5

4

A

7

7

A

6

3.47kΩ

12 34

A , A , A , A = Burr-Brown OPA2604AP,

or equivalent.

3

5

1µF

0.1µF

23

1056

9

–5V

0.1µF

12811

PCM63P

DATA

21

CLK

18

Burr-Brown

LE

4

20

+

4.7µF
8

+5V

1.33kΩ

7.23kΩ

3.92kΩ

+5V

0.1µF
3132

1µF 1µF

+

4.7µF

1µF

+

4.7µF

+5V

Ω17.1k

0.1µF
8

A

φ

121517

BCO

17

+

Digital Interface

4.7µF

Format Receiver

28

6

+5V

Input

Digital

Interleaved

FIGURE 6. Stereo Audio Application.

®

PCM63P

DA

L/R

Yamaha

5

S

1MΩ

(192F )

16.9344MHz

4

YM3623

314

10pF10pF

4700pF

150Ω

10