p89lpc9351 NXP Semiconductors, p89lpc9351 Datasheet - Page 50

• Manufacturer Part Number: p89lpc9351
• Description: 8-bit Microcontroller With Accelerated Two-clock 80c51 Core 8 Kb 3 V Byte-erasable ?ash With 8-bit Adc
• Manufacturer: NXP Semiconductors

NXP Semiconductors
8. ADC
P89LPC9351_1
Preliminary data sheet
7.32 User sector security bytes
8.1 General description
8.2 Features
There are eight User Sector Security Bytes on the P89LPC9351. Each byte corresponds
to one sector. Please see the P89LPC9351 User manual for additional details.
The P89LPC9351 has two 8-bit, 4-channel multiplexed successive approximation
analog-to-digital converter modules. Two high-speed programmable gain amplifiers (PGA)
are integrated. The PGAs provide selectable gains of 2x, 4x, 8x, or 16x. An on-chip
temperature sensor is integrated within one of the ADC and operates over wide
temperature. A block diagram of the ADC is shown in
Both ADCs consist of an 4-input multiplexer which feeds a sample-and-hold circuit
providing an input signal to comparator inputs. The control logic in combination with the
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.
I
I
I
I
I
I
I
I
I
I
I
I
Two 8-bit, 4-channel multiplexed input, successive approximation ADCs.
Programmable Gain Amplifier (PGA) with selectable gains of 2x, 4x, 8x, or 16x.
On-chip wide range temperature sensor.
Four result registers for each A/D.
Six operating modes:
Four conversion start modes:
8-bit conversion time of 1.61 s at an A/D clock of 8.0 MHz.
Interrupt or polled operation.
Boundary limits interrupt.
DAC output to a port pin with high output impedance.
Clock divider.
Power-down mode.
N
N
N
N
N
N
N
N
N
N
Fixed channel, single conversion mode.
Fixed channel, continuous conversion mode.
Auto scan, single conversion mode.
Auto scan, continuous conversion mode.
Dual channel, continuous conversion mode.
Single step mode.
Timer triggered start.
Start immediately.
Edge triggered.
Dual start immediately.
Rev. 01 — 19 November 2008
8-bit microcontroller with 8-bit ADC
Figure 20 “ADC block
P89LPC9351
© NXP B.V. 2008. All rights reserved.
diagram”.
50 of 74