p89lpc904 NXP Semiconductors, p89lpc904 Datasheet - Page 16

• Manufacturer Part Number: p89lpc904
• Description: 8-bit Microcontrollers With Two-clock Accelerated 80c51 Core 1 Kb 3 V Byte-erasable Flash With 8-bit A/d Converter
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 13521
Preliminary data
8.9.1 General description
8.9 A/D converter
The P89LPC904 has an 8-bit, 4-channel multiplexed successive approximation
analog-to-digital converter. A block diagram of the A/D converter is shown in
The A/D consists of a 4-input multiplexer which feeds a sample-and-hold circuit
providing an input signal to one of two comparator inputs. The control logic in
combination with the successive approximation register (SAR) drives a
digital-to-analog converter which provides the other input to the comparator. The
output of the comparator is fed to the SAR.
Fig 5. ADC block diagram.
INPUT
MUX
Rev. 02 — 25 June 2004
8-bit microcontrollers with two-clock accelerated 80C51 core
COMP
+
–
DAC1
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
CCLK
SAR
P89LPC904
8
CONTROL
LOGIC
002aaa783
Figure
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5.