Philips SAA1064, SAA1064T Datasheet

INTEGRATED CIRCUITS

DATA SH EET

SAA1064

4-digit LED-driver with I interface

Product speciﬁcation File under Integrated Circuits, IC01

C-Bus

February 1991

Philips Semiconductors Product speciﬁcation

4-digit LED-driver with I2C-Bus interface

GENERAL DESCRIPTION

The LED-driver is a bipolar integrated circuit made in an I2L compatible 18 volts process. The circuit is especially designed to drive four 7-segment LED displays with decimal point by means of multiplexing between two pairs of digits. It features an I2C-Bus slave transceiver interface with the possibility to program four different SLAVE ADDRESSES, a POWER RESET flag, 16 current sink OUTPUTS, controllable by software up to 21 mA, two multiplex drive outputs for common anode segments, an on-chip multiplex oscillator, control bits to select static, dynamic and blank mode, and one bit for segment test.

QUICK REFERENCE DATA

PARAMETER CONDITIONS SYMBOL MIN. TYP. MAX. UNIT

Supply voltage V Supply current all outputs OFF V Total power dissipation

24-lead DIL (SOT101B) P 24-lead DIL SO (SOT137A) P

Operating ambient

temperature range T

= 0 V V

= 5 V I

tot tot

amb

(1)

SAA1064

4.5 5 15 V 7 9.5 14 mA

−−1000 mW

−−500 mW

−40 − +85 °C

Note

1. The positive current is defined as the conventional current flow into a device (sink current).

PACKAGE OUTLINE

SAA1064: 24-lead DIL; plastic with internal heat spreader (SOT101B); SOT101-1; 1996 August 30. SAA1064T: 24-lead mini-pack; plastic (SO-24; SOT137A); SOT137-1; 1996 August 30.

February 1991 2

Philips Semiconductors Product speciﬁcation

4-digit LED-driver with I2C-Bus interface

SAA1064

February 1991 3

Fig.1 Block diagram.

Philips Semiconductors Product speciﬁcation

4-digit LED-driver with I2C-Bus interface

PINNING

SYMBOL PIN DESCRIPTION

ADR 1 I C

EXT

2 external control P8 to P1 3-10 segment output MX1 11 multiplex output V

12 ground

13 positive supply MX2 14 multiplex output P9 to P16 15-22 segment output SDA 23 I SCL 24 I

C-Bus slave address input

C-Bus serial data line

C-Bus serial clock line

SAA1064

Fig.2 Pinning diagram.

February 1991 4

Philips Semiconductors Product speciﬁcation

4-digit LED-driver with I2C-Bus interface

FUNCTIONAL DESCRIPTION

a. READ mode.

SAA1064

b. WRITE mode.

S = start condition A1, A0 = programmable address bits P = stop condition SC SB SA = subaddress bits A = acknowledge C6 to C0 = control bits X = don’t care PR = POWER RESET ﬂag

Fig.3 I2C-Bus format.

Address pin ADR

Four different slave addresses can be chosen by connecting ADR either to V the corresponding valid addresses HEX 70, 72, 74 and 76 for writing and 71, 73, 75 and 77 for reading. All other addresses cannot be acknowledged by the circuit.

3/8 VCC, 5/8 VCCor VCC. This results in

EE,

February 1991 5

Philips Semiconductors Product speciﬁcation

4-digit LED-driver with I2C-Bus interface

Status byte

Only one bit is present in the status byte, the POWER RESET flag. A logic 1 indicates the occurence of a power failure since the last time it was read out. After completion of the READ action this flag will be set to logic 0.

Subaddressing

The bits SC, SB and SA form a pointer and determine to which register the data byte following the instruction byte will be written. All other bytes will then be stored in the registers with consecutive subaddresses. This feature is called Auto-Increment (AI) of the subaddress and enables a quick initialization by the master. The subaddress pointer will wrap around from 7 to 0. The subaddresses are given as follows:

SC SB SA SUB-ADDRESS FUNCTION

0 0 0 00 control register 0 0 1 01 digit 1 0 1 0 02 digit 2 0 1 1 03 digit 3 1 0 0 04 digit 4 1 0 1 05 reserved, not used 1 1 0 06 reserved, not used 1 1 1 07 reserved, not used

SAA1064

Control bits (see Fig.4) The control bits C0 to C6 have the following meaning:

C0 = 0 static mode, i.e. continuous display of digits 1 and 2 C0 = 1 dynamic mode, i.e. alternating display of digit 1 + 3 and 2 + 4 C1 = 0/1 digits 1 + 3 are blanked/not blanked C2 = 0/1 digits 2 + 4 are blanked/not blanked C3 = 1 all segment outputs are switched-on for segment test C4 = 1 adds 3 mA to segment output current C5 = 1 adds 6 mA to segment output current C6 = 1 adds 12 mA to segment output current

Note

1. At a current determined by C4, C5 and C6.

Data

A segment is switched ON if the corresponding data bit is logic 1. Data bits D17 to D10 correspond with digit 1, D27 to D20 with digit 2, D37 to D30 with digit 3 and D47 to D40 with digit 4.

The MSBs correspond with the outputs P8 and P16, the LSBs with P1 and P9. Digit numbers 1 to 4 are equal to their subaddresses (hex) 1 to 4.

(1)

February 1991 6

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