Key Features
4-channel Pulse Width Modulator (PWM) generator
-- Configurable resolution 1 10 bits
4-channel, 8-bit Analog-to-Digital Converter
-- 9.3 microseconds conversion time at 20 MHz
-- 100% accelerated C51 CPU core runs at 6 clocks
per instruction
20 MHz maximum operating frequency 4.5 6.0V and
10 MHz maximum operating frequency 2.7 6.0V
Configurable brownout reset detector
On-chip serial communications interfaces
-- UART
-- I
2
C
Five I/O pin modes, individually selectable for each pin
-- Quasi bi-directional
-- Push-pull output
-- Open drain output
-- Input
-- Schmitt trigger input
Up to 18 pins usable for general purpose I/O
Low Power, Low System Cost
80C51 MCU with ADC and PWM
P87LPC768
As a member of the 51LPC microcontroller family, the 87LPC768
offers an 8-bit ADC with four multiplexed channels and an 8-bit
Pulse Width Modulator (PWM.) Further, the device provides 4K
of OTP code memory and 128 bytes of data SRAM, making it
suitable for high-level programming. The code memory is In-System
Programmable (ISP) through a serial interface. Other embedded
features that reduce the need for external components are brownout
detection, power-on reset and an on-chip RC oscillator that is very
stable over temperature and voltage.
The MCU core is fully compatible with the industry-standard C51
core, but features a 2X speed mode, where the CPU clock is divided
by 6 instead of 12. At 20 MHz, the 51LPC family devices provide
a throughput identical to a conventional C51 running at 40 MHz,
thus minimizing EMI and power consumption. The 87LPC768 is
manufactured in Philips Semiconductor's low-power CMOS tech-
nology and is well suited for use in battery powered applications.
At 32kHz, the device consumes only 16A and the operating volt-
age ranges from 2.7 6.0V (3.0 6.0V for analog peripherals). A
fixed-frequency oscillator running at 6 MHz can be used to clock
the device in applications that do not require the high accuracy of
a crystal. Regardless of the clock source used, the user can reduce
operating frequency down to as much 1/512 of the source frequen-
cy, allowing the user to optimize performance and power consump-
tion on-the-fly. Use of the on-chip power-on reset and oscillator
makes up to 18 I/O pins available to the user, leaving only two
non-I/O pins for connection to power and ground.
Because the P87LPC768 combines an embedded ADC and PWM,
it is especially useful in applications that include dynamic position-
ing, speed and temperature control. The PWM provides very
high flexibility since the output resolution can be configured to
any number of bits up to 10.
The device comes with extensive serial communication capabilities.
On-chip UART provides serial communications for RS-232 and
RS-485. The I
2
C interface provides interface to other I
2
C units
such as serial EEPROMs, other MCUs and a variety of peripheral
devices. These communications interfaced in combination with
the analog capabilities makes the 87LPC768 ideal for a variety of
sensor applications.
The P87LPC768 is available in 20-pin SOIC and PDIP packages
Ordering Information
Part Number
Temperature (C)
Package Description
Operating Frequency
P87LPC768BN
0 to +70
Plastic Dual In-Line [PDIP20]
All devices operate at
P87LPC768BD
0 to +70
Plastic Small Outline [SOIC20]
20MHz @ 4.5 to 6.0V
P87LPC768FN
40 to +85
Plastic Dual In-Line [PDIP20]
10MHz @ 2.7 to 6.0V
P87LPC768FD
40 to +85
Plastic Small Outline [SOIC20]
P87LPC768
Low Power, Low System Cost 80C51 MCU with ADC and PWM
P87LPC768
For more information, contact your Philips Semiconductors distributor or www.PhilipsMCU.com
N
orth America
Europe
Asia
Japan/Korea
Tel: 1 800 234-7381
Fax: +31 79 3685126
Fax: 886 2 2134-2941
Fax: +81-3-3740-5057
Internet:
Internet (in Japanese):
www.PhilipsMCU.com
www.philips.co.jp/semicon/
Philips Electronics N.V. 2000
All rights reserved. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The information presented in this document
does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. No liability will be accepted by the publisher for
any consequence of its use. Publication thereof does not convey nor imply any license under patent - or industrial or intellectual property rights.
Printed in the USA 611651/14K/FP/2pp/0500
9397-750-07045
LPC768 Block Diagram
Features
An accelerated 80C51 CPU provides instruction cycle
times of 300600 ns for all instructions except multiply
and divide when executing at 20 MHz. Execution at up
to 20 MHz when V
DD
= 4.5 V to 6.0 V, 10 MHz when
V
DD
= 2.7 V to 6.0 V.
Four-channel Pulse Width Modulator.
Four-channel multiplexed 8-bit A/D converter.
Conversion time of 9.3 microseconds at f
osc
= 20 MHz.
2.7 V to 6.0 V operating range for digital functions.
4 K bytes OTP memory.
128 byte RAM data memory.
32-byte customer code EPROM allows serialization of
devices, storage of setup parameters, etc.
Two 16-bit counter/timers. Each timer may be
configured to toggle a port output upon timer overflow.
4K BYTE
CODE EPROM
INTERNAL
BUS
ACCELERATED
80C51 CPU
128 BYTE
DATA RAM
PORT 2
CONFIGURABLE I/Os
PORT 1
CONFIGURABLE I/Os
PORT 0
CONFIGURABLE I/Os
KEYPAD
INTERRUPT
UART
I2C
TIMER 0, 1
WATCHDOG TIMER
AND OSCILLATOR
ANALOG
COMPARATORS
A/D
CONVERTER
PULSE WIDTH
MODULATOR
CONFIGURABLE
OSCILLATOR
ON-CHIP R/C
OSCILLATOR
CRYSTAL OR
RESONATOR
POWER MONITOR
(POWER-ON RESET,
BROWNOUT RESET)
Two analog comparators.
Full duplex UART.
I
2
C communication port.
Eight keypad interrupt inputs, plus two additional external
interrupt inputs.
Four interrupt priority levels.
Watchdog timer with separate on-chip oscillator, requiring
no external components. The watchdog timeout time is
selectable from 8 values.
Active low reset. On-chip power-on reset allows operation
with no external reset components.
Low voltage reset. One of two preset low voltage levels may
be selected to allow a graceful system shutdown when power
fails. May optionally be configured as an interrupt.
Oscillator Fail Detect. The watchdog timer has a separate
fully on-chip oscillator, allowing it to perform an oscillator
fail detect function.
Configurable on-chip oscillator with frequency range and
RC oscillator options (selected by user programmed
EPROM bits). The RC oscillator option allows operation
with no external oscillator components.
Programmable port output configuration options:
quasi-bidirectional, open drain, push-pull, input-only.
Selectable Schmitt trigger port inputs.
LED drive capability (20 mA) on all port pins.
Controlled slew rate port outputs to reduce EMI. Outputs
have approximately 10 ns minimum ramp times.
15 I/O pins minimum. Up to 18 I/O pins using on-chip
oscillator and reset options.
Only power and ground connections are required to operate
the 87LPC768 when fully on-chip oscillator and reset
options are selected.
Serial EPROM programming allows simple in-circuit
production coding. Two EPROM security bits prevent
reading of sensitive application programs.
Idle and Power Down reduced power modes. Improved
wakeup from Power Down mode (a low interrupt input
starts execution). Typical Power Down current is
1 microamp.
20-pin DIP and SO packages.
PDF 
ZIP