Philips PCF8576CH, PCF8576CU-12, PCF8576CU-2, PCF8576CU-5, PCF8576CU Datasheet

INTEGRATED CIRCUITS

DATA SHEET

PCF8576C

Universal LCD driver for low multiplex rates

Product specification

2001 Oct 02

Supersedes data of 1998 Jul 30

File under Integrated Circuits, IC12

Philips Semiconductors	Product specification
Universal LCD driver for low multiplex rates	PCF8576C

CONTENTS

1FEATURES

2GENERAL DESCRIPTION

3ORDERING INFORMATION

4BLOCK DIAGRAM

5PINNING

6FUNCTIONAL DESCRIPTION

6.1Power-on reset

6.2LCD bias generator

6.3LCD voltage selector

6.4LCD drive mode waveforms

6.5Oscillator

6.5.1Internal clock

6.5.2External clock

6.6Timing

6.7Display latch

6.8Shift register

6.9Segment outputs

6.10Backplane outputs

6.11Display RAM

6.12Data pointer

6.13Subaddress counter

6.14Output bank selector

6.15Input bank selector

6.16Blinker

7	CHARACTERISTICS OF THE I2C-BUS

7.1Bit transfer (see Fig.12)

7.2START and STOP conditions (see Fig.13)

7.3System configuration (see Fig.14)

7.4Acknowledge (see Fig.15)

7.5PCF8576C I2C-bus controller

7.6Input filters

7.7I2C-bus protocol

7.8Command decoder

7.9Display controller

7.10Cascaded operation

8LIMITING VALUES

9HANDLING

10DC CHARACTERISTICS

11AC CHARACTERISTICS

11.1Typical supply current characteristics

11.2Typical characteristics of LC D outputs

12 APPLICATION INFORMATION

12.1 Chip-on-glass cascadability in single plane

13BONDING PAD INFORMATION

14TRAY INFORMATION: PCF8576CU and PCF8576CU/2

15PACKAGE OUTLINES

16SOLDERING

16.1Introduction to soldering surface mount packages

16.2Reflow soldering

16.3Wave soldering

16.4Manual soldering

16.5Suitability of surface mount IC packages for wave and reflow soldering methods

17DATA SHEET STATUS

18DEFINITIONS

19DISCLAIMERS

20PURCHASE OF PHILIPS I2C COMPONENTS

2001 Oct 02

2

Philips Semiconductors	Product specification
Universal LCD driver for low multiplex rates	PCF8576C

1 FEATURES

·Single-chip LCD controller/driver

·Selectable backplane drive configuration: static or 2/3/4 backplane multiplexing

·Selectable display bias configuration: static, 1¤2 or 1¤3

·Internal LCD bias generation with voltage-follower buffers

·40 segment drives: up to twenty 8-segment numeric characters; up to ten 15-segment alphanumeric characters; or any graphics of up to 160 elements

·40 ´ 4-bit RAM for display data storage

·Auto-incremented display data loading across device subaddress boundaries

·Display memory bank switching in static and duplex drive modes

·Versatile blinking modes

·LCD and logic supplies may be separated

·Wide power supply range: from 2 V for low-threshold LCDs and up to 6 V for guest-host LCDs and high-threshold (automobile) twisted nematic LCDs.

A 9 V version is also available on request.

·Low power consumption

·Power-saving mode for extremely low power consumption in battery-operated and telephone applications

·I2C-bus interface

·TTL/CMOS compatible

·Compatible with any 4-bit, 8-bit or 16-bit microprocessors/microcontrollers

3 ORDERING INFORMATION

·May be cascaded for large LCD applications (up to 2560 segments possible)

·Cascadable with 24-segment LCD driver PCF8566

·Optimized pinning for plane wiring in both and multiple PCF8576C applications

·Space-saving 56-lead plastic very small outline package (VSO56) or 64-lead low profile quad flat package (LQFP64)

·No external components

·Compatible with chip-on-glass technology

·Manufactured in silicon gate CMOS process.

2 GENERAL DESCRIPTION

The PCF8576C is a peripheral device which interfaces to almost any Liquid Crystal Display (LCD) with low multiplex rates. It generates the drive signals for any static or multiplexed LCD containing up to four backplanes and up to 40 segments and can easily be cascaded for larger LCD applications. The PCF8576C is compatible with most microprocessors/microcontrollers and communicates via a two-line bidirectional I2C-bus. Communication overheads are minimized by a display RAM with auto-incremented addressing, by hardware subaddressing and by display memory switching (static and duplex drive modes).

	TYPE NUMBER		PACKAGE
		NAME	DESCRIPTION	VERSION
	PCF8576CT	VSO56	plastic very small outline package; 56 leads	SOT190-1
	PCF8576CU	-	chip in tray	-
	PCF8576CU/2	-	chip with bumps in tray	-
	PCF8576CU/5	-	unsawn wafer	-
	PCF8576CU/10	FFC	chip-on-film frame carrier	-
	PCF8576CU/12	FFC	chip with bumps on film frame carrier	-
	PCF8576CH	LQFP64	plastic low profile quad flat package; 64 leads; body 10 ´ 10 ´ 1.4 mm	SOT314-2

2001 Oct 02

3

	_
02 Oct 2001											BLOCK 4
				BP0 BP2 BP1 BP3				S0 to S39			DIAGRAM
								40
				13	14	15	16	17 to 56
	5			BACKPLANE
	VDD						DISPLAY SEGMENT OUTPUTS
				OUTPUTS
			LCD					DISPLAY LATCH
			VOLTAGE
			SELECTOR
		LCD BIAS						SHIFT REGISTER
		GENERATOR
	12
	VLCD
4	4			PCF8576C			INPUT	DISPLAY	OUTPUT
	CLK	TIMING	BLINKER
	3						BANK	RAM	BANK
	SYNC						SELECTOR	40 x 4 BITS	SELECTOR
				DISPLAY
				CONTROLLER
	6	OSCILLATOR	POWER-
	OSC							DATA
			ON
								POINTER
			RESET
	11			COMMAND
	VSS			DECODER
	2									SUB-
	SCL	INPUT	I2C - BUS						ADDRESS
	1	FILTERS	CONTROLLER						COUNTER
	SDA
			10						7	8	9
			SA0						A0	A1	A2
											MLD332

Fig.1 Block diagram; VSO56.

rates multiplex low for driver LCD Universal

PCF8576C

Semiconductors Philips

specification Product

Philips Semiconductors						Product specification
	Universal LCD driver for low multiplex rates					PCF8576C
5 PINNING
	SYMBOL				PIN	DESCRIPTION
				SOT190	SOT314
	SDA			1	10	I2C-bus serial data input/output
	SCL			2	11	I2C-bus serial clock input
				3	12	cascade synchronization input/output
	SYNC
	CLK			4	13	external clock input
	VDD			5	14	supply voltage
	OSC			6	15	oscillator input
	A0 to A2			7 to 9	16 to 18	I2C-bus subaddress inputs
	SA0			10	19	I2C-bus slave address input; bit 0
	VSS			11	20	logic ground
	VLCD			12	21	LCD supply voltage
	BP0, BP2, BP1, BP3			13 to 16	25 to 28	LCD backplane outputs
	S0 to S39			17 to 56	29 to 32, 34 to 47, 49 to 64, 2 to 7	LCD segment outputs
	n.c.			−	1, 8, 9, 22 to 24, 33 and 48	not connected

2001 Oct 02

5

Philips Semiconductors	Product specification
Universal LCD driver for low multiplex rates	PCF8576C

SDA		1		56	S39
SCL		2		55	S38
SYNC		3		54	S37
CLK		4		53	S36
VDD
		5		52	S35
OSC		6		51	S34
A0		7		50	S33
A1		8		49	S32
A2		9		48	S31
SA0		10		47	S30
VSS
		11		46	S29
VLCD
		12		45	S28
BP0		13		44	S27
BP2		14	PCF8576CT	43	S26
BP1		15		42	S25
BP3		16		41	S24
S0		17		40	S23
S1		18		39	S22
S2		19		38	S21
S3		20		37	S20
S4		21		36	S19
S5		22		35	S18
S6		23		34	S17
S7		24		33	S16
S8		25		32	S15
S9		26		31	S14
S10		27		30	S13
S11		28		29	S12
			MLD334

Fig.2 Pin configuration; VSO56.

2001 Oct 02

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Philips Semiconductors	Product specification
Universal LCD driver for low multiplex rates	PCF8576C

handbook, full pagewidth

S33		S32		S31		S30		S29		S28		S27		S26		S25		S24		S23		S22		S21		S20		S19		S18
64		63		62		61		60		59		58		57		56		55		54		53		52		51		50		49

n.c. 1 S34 2 S35 3 S36 4 S37 5 S38 6 S39 7

n.c. 8

PCF8576CH

n.c. 9 SDA 10 SCL 11 SYNC 12 CLK 13 VDD 14 OSC 15 A0 16

17		18		19		20		21		22		23		24		25		26		27		28		29		30		31		32
A1		A2		SA0		V		LCD		n.c.		n.c.		n.c.		BP0		BP2		BP1		BP3		S0		S1		S2		S3
						SS
								V

48 n.c.

47 S17

46 S16

45 S15

44 S14

43 S13

42 S12

41 S11

40 S10

39 S9

38 S8

37 S7

36 S6

35 S5

34 S4

33 n.c.

MLD333

Fig.3 Pin configuration; LQFP64.

2001 Oct 02

7

Philips Semiconductors	Product specification
Universal LCD driver for low multiplex rates	PCF8576C

6 FUNCTIONAL DESCRIPTION

The PCF8576C is a versatile peripheral device designed to interface to any microprocessor/microcontroller to a wide variety of LCDs. It can directly drive any static or multiplexed LCD containing up to four backplanes and up to 40 segments. The display configurations possible with the PCF8576C depend on the number of active backplane outputs required; a selection of display configurations is given in Table 1.

All of the display configurations given in Table 1 can be implemented in the typical system shown in Fig.4.

The host microprocessor/microcontroller maintains the 2-line I2C-bus communication channel with the PCF8576C. The internal oscillator is selected by tying OSC (pin 6) to VSS (pin 11). The appropriate biasing voltages for the multiplexed LCD waveforms are generated internally. The only other connections required to complete the system are to the power supplies (VDD,

VSS and VLCD) and the LCD panel chosen for the application.

Table 1 Selection of display configurations

	NUMBER OF		7-SEGMENTS NUMERIC			14-SEGMENTS
					ALPHANUMERIC
								DOT MATRIX
	BACKPLANES	SEGMENTS	DIGITS	INDICATOR	CHARACTERS		INDICATOR
				SYMBOLS			SYMBOLS
	4	160	20	20	10		20	160 dots (4 × 40)
	3	120	15	15	8		8	120 dots (3 × 40)
	2	80	10	10	5		10	80 dots (2 × 40)
	1	40	5	5	2		12	40 dots (1 × 40)

VDD

R

tr

2CB

V

V

LCD

DD

SDA

5

12

HOST

1

17 to 56

40 segment drives

LCD PANEL

MICRO-

SCL

PCF8576CT

PROCESSOR/

2

(up to 160

MICRO-

OSC

elements)

CONTROLLER

6

13 to 16

4 backplanes

7

8

9

10

11

VSS

A0

A1

A2

SA0

VSS

MBE524

Fig.4 Typical system configuration.

2001 Oct 02

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Philips Semiconductors	Product specification
Universal LCD driver for low multiplex rates	PCF8576C

6.1Power-on reset

At power-on the PCF8576C resets to a starting condition as follows:

1.All backplane outputs are set to VDD.

2.All segment outputs are set to VDD.

3.The drive mode ‘1 : 4 multiplex with 1¤3bias’ is selected.

4.Blinking is switched off.

5.Input and output bank selectors are reset (as defined in Table 5).

6.The I2C-bus interface is initialized.

7.The data pointer and the subaddress counter are cleared.

Data transfers on the I2C-bus should be avoided for 1 ms following power-on to allow completion of the reset action.

6.2LCD bias generator

The full-scale LCD voltage (Vop) is obtained from

VDD - VLCD. The LCD voltage may be temperature compensated externally through the VLCD supply to pin 12.

Fractional LCD biasing voltages are obtained from an internal voltage divider of the three series resistors connected between VDD and VLCD. The centre resistor can be switched out of the circuit to provide a 1¤2bias voltage level for the 1 : 2 multiplex configuration.

6.3LCD voltage selector

The LCD voltage selector co-ordinates the multiplexing of the LCD in accordance with the selected LCD drive configuration. The operation of the voltage selector is controlled by MODE SET commands from the command decoder. The biasing configurations that apply to the preferred modes of operation, together with the biasing

characteristics as functions of Vop = VDD - VLCD and the resulting discrimination ratios (D), are given in Table 2.

A practical value for Vop is determined by equating Voff(rms) with a defined LCD threshold voltage (Vth), typically when

the LCD exhibits approximately 10% contrast. In the static drive mode a suitable choice is Vop > 3Vth approximately.

Multiplex drive ratios of 1 : 3 and 1 : 4 with 1¤2bias are possible but the discrimination and hence the contrast

ratios are smaller ( 3 = 1.732 for 1 : 3 multiplex or

21

---------- = 1.528 for 1 : 4 multiplex). 3

The advantage of these modes is a reduction of the LCD full-scale voltage Vop as follows:

·	1 : 3 multiplex (1¤2bias):
	Vop =		6 ´ Voff á rmsñ = 2.449 Voff(rms)
·	1 : 4 multiplex (1¤2bias):
	V	=	(4 ´ 3)	= 2.309 V	off(rms)
		op	---------------------
			3

These compare with Vop = 3 Voff(rms) when 1¤3bias is used.

Table 2 Preferred LCD drive modes: summary of characteristics

	NUMBER OF		LCD BIAS	Voff(rms)	Von(rms)	Von(rms)
LCD DRIVE MODE				--------------------	--------------------	D = --------------------
	BACKPLANES	LEVELS	CONFIGURATION	Vop	Vop	Voff(rms)
static	1	2	static	0	1	¥
1 : 2	2	3	1¤2	0.354	0.791	2.236
1 : 2	2	4	1¤3	0.333	0.745	2.236
1 : 3	3	4	1¤3	0.333	0.638	1.915
1 : 4	4	4	1¤3	0.333	0.577	1.732

2001 Oct 02

9

Philips Semiconductors	Product specification
Universal LCD driver for low multiplex rates	PCF8576C

6.4LCD drive mode waveforms

The static LCD drive mode is used when a single backplane is provided in the LCD. Backplane and segment drive waveforms for this mode are shown in Fig.5.

When two backplanes are provided in the LCD, the 1 : 2 multiplex mode applies. The PCF8576C allows use of 1¤2bias or 1¤3bias in this mode as shown in Figs 6 and 7.

When three backplanes are provided in the LCD, the 1 : 3 multiplex drive mode applies, as shown in Fig.8.

When four backplanes are provided in the LCD, the 1 : 4 multiplex drive mode applies, as shown in Fig.9.

V DD

BP0

VLCD

V DD

Sn

VLCD

VDD

S n 1

VLCD

Tframe

LCD segments

state 1	state 2
(on)	(off)

(a) waveforms at driver

V op

state 1

0

Vop

V op

state 2

0

Vop

(b) resultant waveforms
at LCD segment	MBE539

Vstate1(t) = VSn(t) –VBP0(t)

Von(rms) = Vop

Vstate2(t) = VSn + 1(t) –VBP0(t)

Voff(rms) = 0 V

Fig.5 Static drive mode waveforms (Vop = VDD - VLCD).

2001 Oct 02

10

Philips Semiconductors	Product specification
Universal LCD driver for low multiplex rates	PCF8576C

VDD

Tframe

LCD segments

BP0

(VDD

VLCD )/2

VLCD

state 1

VDD

state 2

BP1

(VDD

VLCD )/2

VLCD

Sn

VDD

VLCD

S n

1

VDD

VLCD

(a) waveforms at driver

Vop

Vop /2

state 1

0

Vop /2

Vop

Vop

Vop /2

state 2

0

Vop /2

Vop

(b) resultant waveforms

MBE540

at LCD segment

Vstate1(t) = VSn(t) –VBP0(t)

Von(rms) = 0.791Vop

Vstate2(t) = VSn(t) –VBP1(t)

Voff(rms) = 0.354Vop

Fig.6 Waveforms for the 1 : 2 multiplex drive mode with 1¤2bias (Vop = VDD - VLCD).

2001 Oct 02

11

Philips Semiconductors	Product specification
Universal LCD driver for low multiplex rates	PCF8576C

BP0

BP1

Sn

S n 1

state 1

state 2

VDD

Tframe

LCD segments

VDD

Vop /3

VDD

2Vop /3

VLCD

state 1

VDD

state 2

VDD

Vop /3

VDD

2Vop /3

VLCD

VDD

VDD

Vop /3

VDD

2Vop /3

VLCD

VDD

VDD

Vop /3

VDD

2Vop /3

VLCD

(a) waveforms at driver

Vop

2Vop /3

Vop /3

0

Vop /3

2Vop /3

Vop

Vop

2Vop /3

Vop /3

0

Vop /3

2Vop /3

Vop

	(b) resultant waveforms	MBE541
	at LCD segment

Vstate1(t) = VSn(t) –VBP0(t)

Von(rms) = 0.745Vop

Vstate2(t) = VSn(t) –VBP1(t)

Voff(rms) = 0.333Vop

Fig.7 Waveforms for the 1 : 2 multiplex drive mode with 1¤3bias (Vop = VDD - VLCD).

2001 Oct 02

12

Philips Semiconductors	Product specification
Universal LCD driver for low multiplex rates	PCF8576C

VDD

BP0

VDD

Vop /3

VDD

2Vop /3

VLCD

VDD

BP1

VDD

Vop /3

VDD

2Vop /3

VLCD

VDD

BP2/S23

VDD

Vop /3

VDD

2Vop /3

VLCD

VDD

S n

VDD

Vop /3

VDD

2Vop /3

VLCD

VDD

Sn

1

VDD

Vop /3

VDD

2Vop /3

VLCD

VDD

Sn

2

VDD

Vop /3

VDD

2Vop /3

VLCD

Vop

2V op /3

Vop /3

state 1

0

Vop /3

2V op /3

Vop

Vop

2V op /3

Vop /3

state 2

0

Vop /3

2V op /3 Vop

Vstate1(t) = VSn(t) –VBP0(t)

Von(rms) = 0.638Vop

Vstate2(t) = VSn(t) –VBP1(t)

Voff(rms) = 0.333Vop

Tframe

(a) waveforms at driver

LCD segments

state 1

state 2

(b) resultant waveforms	MBE542
at LCD segment

Fig.8 Waveforms for the 1 : 3 multiplex drive mode (Vop = VDD − VLCD).

2001 Oct 02

13

Philips Semiconductors	Product specification
Universal LCD driver for low multiplex rates	PCF8576C

BP0

BP1

BP2

BP3

Sn

Sn 1

S n 2

Sn 3

state 1

state 2

VDD

Tframe

VDD

Vop /3

VDD

2Vop /3

VLCD

VDD

VDD

Vop /3

VDD

2Vop /3

VLCD

VDD

VDD

Vop /3

VDD

2Vop /3

VLCD

VDD

VDD

Vop /3

VDD

2Vop /3

VLCD

VDD

VDD

Vop /3

VDD

2Vop /3

VLCD

VDD

VDD

Vop /3

VDD

2Vop /3

VLCD

VDD

VDD

Vop /3

VDD

2Vop /3

VLCD

VDD

VDD

Vop /3

VDD

2Vop /3

VLCD

(a) waveforms at driver

Vop
2Vop /3
Vop /3
0
Vop /3
2Vop /3
Vop
Vop
2Vop /3
Vop /3
0
Vop /3
2Vop /3
Vop	(b) resultant waveforms
	at LCD segment

LCD segments

state 1

state 2

Vstate1(t) = VSn(t) –VBP0(t)

Von(rms) = 0.577Vop

Vstate2(t) = VSn(t) –VBP1(t)

MBE543 Voff(rms) = 0.333Vop

Fig.9 Waveforms for the 1 : 4 multiplex drive mode (Vop = VDD − VLCD).

2001 Oct 02

14