PCM1794A
ZHCSEE9B –AUGUST 2004–REVISED DECEMBER 2015
www.ti.com.cn
7 Detailed Description
7.1 Overview
The PCM1794A device is a 24-bit, 192-kHz, differential-current, output digital-to-analog converter (DAC) that
comes in a 28-pin SSOP package. The PCM1794AA device is hardware controlled and uses the advanced-
segment DAC architecture from TI to perform with a Stereo Dynamic Range of 129 dB (132 dB Mono) and with a
THD of 0.0004% at 44.1 kHz. The PCM1794AA device uses the SCK input as the system clock and
automatically detects the sampling rate of the Digital Audio input when valid BCK and LRCK clocks are supplied.
To bypass the internal filter, use an external digital filter.
Table 1. Device Features
FEATURE
DESCRIPTION
Resolution
24 bits
Audio data interface format
Audio data bit length
Audio data format
Standard, I2S, left justified
16-bit, 24-bit selectable
MSB first, two's complement
7.2 Functional Block Diagram
I
I
L–
OUT
LRCK
Audio
BCK
Data Input
DATA
Current
Segment
DAC
V
L
OUT
I/F
L+
L
OUT
I/V and Filter
8
Oversampling
Digital
V
I
COM
MUTE
FMT1
FMT0
MONO
CHSL
Advanced
Segment
DAC
Bias
and
Vref
REF
Filter
and
V
R
COM
Modulator
Function
Control
Function
Control
I/F
I
R–
OUT
OUT
Current
Segment
DAC
V
OUT
R
DEM
RST
I
R+
I/V and Filter
System
Clock
Manager
ZERO
Zero
Power Supply
Detect
12
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