ST2225A. LED Display Driver. Version : A.025 Issue Date : 2001/11/26 File Name Total Pages : 12. : SP-ST2225A-A.025.doc

Transcription

1 Version : A.025 Issue Date : 2001/11/26 File Name Total Pages : 12 : SP--A.025.doc LED Display Driver 新竹市科學園區展業㆒路 9 號 7 樓之 1 9-7F-1, Prosperity Road I, Science Based Industrial Park, Hsin-Chu, Taiwan 300, R.O.C. Tel: Fax:

2 LED Display Driver General Description The LED display driver is a monolithic CMOS IC. In order to achieve continuous brightness control, the LED display brightness is controlled by setting a reference current through a variable resistor connected between a supply and a single pin. Features n" Continuous brightness control n" Serial data input n" No load signal required for data latch n" Wide power supply operation n" TTL compatibility n" 35 outputs, 20mA capability n" Small package, SSOP48 and bare chip form Applications n" Industrial control indicator n" Relay driver n" Digital clock, thermometer, counter, voltmeter n" Instrumentation readouts Ordering Information Part Number Temp. Range Package -SS3-40 to +85 SSOP48 -D -40 to +85 Bare Chip LED Display Driver -1- Version:A.025

3 Block Diagram BRIGHTNESS CONTROL VDD OUT35 OUT OUTPUT BUFFERS 29 DATA ENABLE 35 LATCHES LOAD 28 SERIAL DATA 35-BIT SHIFT REGISTERS 27 CLOCK RESET 20 1,13,36 RESET Figure 1 Connection Diagram : SSOP48 Package VSS OUTPUT BIT OUTPUT BIT18 OUTPUT BIT19 OUTPUT BIT OUTPUT BIT20 OUTPUT BIT OUTPUT BIT21 OUTPUT BIT14 OUTPUT BIT13 OUTPUT BIT OUTPUT BIT22 OUTPUT BIT23 OUTPUT BIT24 OUTPUT BIT11 OUTPUT BIT10 OUTPUT BIT 9 OUTPUT BIT 8 OUTPUT BIT 7 VSS OUTPUT BIT 6 OUTPUT BIT SS OUTPUT BIT25 OUTPUT BIT26 OUTPUT BIT27 OUTPUT BIT28 OUTPUT BIT29 VSS OUTPUT BIT30 OUTPUT BIT31 OUTPUT BIT OUTPUT BIT32 OUTPUT BIT OUTPUT BIT33 OUTPUT BIT OUTPUT BIT34 OUTPUT BIT OUTPUT BIT35 RESET DATA ENABLE BRIGHTNESS CONTROL VDD N/A N/A DATA CLOCK N/A N/A Figure 2 LED Display Driver -2- Version:A.025

4 Die Configuration OUTPUT BIT 14 OUTPUT BIT 15 OUTPUT BIT 16 OUTPUT BIT 17 VSS OUTPUT BIT 18 OUTPUT BIT 19 OUTPUT BIT 20 OUTPUT BIT 21 OUTPUT BIT 22 OUTPUT BIT 13 OUTPUT BIT 12 OUTPUT BIT 11 OUTPUT BIT 10 OUTPUT BIT 9 OUTPUT BIT 8 OUTPUT BIT 7 VSS OUTPUT BIT 6 OUTPUT BIT 5 OUTPUT BIT 4 OUTPUT BIT 3 OUTPUT BIT 2 OUTPUT BIT 1 -D OUTPUT BIT 23 OUTPUT BIT 24 OUTPUT BIT 25 OUTPUT BIT 26 OUTPUT BIT 27 OUTPUT BIT 28 OUTPUT BIT 29 VSS OUTPUT BIT 30 OUTPUT BIT 31 OUTPUT BIT 32 OUTPUT BIT 33 OUTPUT BIT 34 OUTPUT BIT 35 Die Size: um * 2614um Pad Size: 100um * 100um (0, 0) RESET VDD BRIGHTNESS CONTROL CLK DATA DATA ENABLE Figure 3 * Note: SiTI reserves the right to improve the device geometry and manufacturing processes without prior notice. Though these improvements may result in slight geometry changes, they will not affect die electrical characteristics and pad layouts. Wafer Information Material: Silicon with P-Substrate Diameter: 6 inches( 15cm) Thickness: 12 mils( 300um) Width of scribe line:100um Malfunctioned die:marked with red ink or equivalent marking LED Display Driver -3- Version:A.025

5 Pad Allocation for the Bare Chip, -D PAD Name Center Coordinate Center Coordinate PAD Name (X,Y) um (X,Y) um VSS CLK OUTPUT DATA OUTPUT DATAENZ OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT VSS OUTPUT OUTPUT OUTPUT OUTPUT VSS OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT RESET OUTPUT IBRIGHT OUTPUT VDD OUTPUT LED Display Driver -4- Version:A.025

6 Absolute Maximum Ratings Voltage (any pin)...vss to Vss +12V Power Dissipation (P D ) W mW Junction Temperature (Tj) Storage Temperature (Ts) to +150 Lead Temperature (soldering, 10 sec.) Electrical Characteristics 4.5V V DD 11V, Vss=0V; T A =25, bold values indicate -40 T A +85 ;unless noted Symbol Parameter Condition Min Typ Max Units -25 to +85, excluding output loads 5 m A I DD Power Supply Current -40 to +85, excluding output loads 6 m A VIL Low-level Data Input Voltage logic-0 level, ±10μA input bias V logic-1 level, 4.75V VDD 5.25V 2.2 VDD V VIH High-level Data Input Voltage logic-1 level, VDD>5.25V VDD-2 VDD V I BC Brightness Control Input Current Note m A I OUT OFF Output Sink Current When OFF Segment off, VOUT=3.0V 10 μa I OUT ON Output Sink Current When ON Segment on, VOUT=1.0V, Note 3 Brightness input =0μA Brightness input =100μA Brightness input =750μA V BC Brightness Control Input Voltage Input Current =750μA V R MATCH Output Matching Note 1 ±20 % fc Clock Input Frequency Notes 4, khz th Clock Input High Time Notes 4, ns tl Clock Input Low Time Notes 4, ns tds Data Input Setup Time 300 ns tdh Data Input Hold Time 300 ns tdes Data Enable Input Setup Time 100 ns Note 1: Output matching is calculated as the percent variation (IMAX + IMIN) / 2 Note 2: With a fixed resistor on the brightness input pin, some variation in brightness will occur among devices. Note 3: VOUT should be so regulated that power dissipation of the chip will not exceed its limit. Note 4: AC input waveform specification for test purpose: tr 20ns, tf 20ns, t=500khz, 50%±10% duty cycle. Note 5: Clock input rise and fall times must not exceed 300ns μa m A m A LED Display Driver -5- Version:A.025

7 Operating Ratings Supply Voltage (VDD VSS) V to 11V Ambient Temperature Range (TA) to +85 Functional Description The display driver can drive either 4- or 5-digit alphanumeric LED displays. One of its advantages is its minimal interface requirement with the display or data source. Data transfer is accomplished by sending clock and serial data signals, without any need of an external load signal. This method provides a non-multiplexed, direct drive to the LED display. The data transfer format uses a leading 1 followed by 35 data bits. These 35 data bits are latched after the 36 th has been transferred. In this way, data output (refers to the currently displayed characters) changes only if the serial data bits differ from those previously transferred. Display brightness is controlled by the output current for LED displays. A 1nF capacitor should be connected to brightness control pin to prevent oscillations. Figure 1 shows the block diagram of this driver. The output current is set via an external variable resistor, and is typically 27 times greater than the current in brightness control pin. Input data format, as in Figure 4, shows a leading 1 followed by 35 data bits. When the 36 th is transferred, a LOAD signal is generated synchronously with the clock high state, thus, the 35 bits of data are loaded into the latches. The low state of the clock is used to generate a RESET signal to clear all shift registers for the next set of data. To allow continuous operation, all shift registers are static master-slaves, with no clear for the master portion of the first register. LED Display Driver -6- Version:A.025

8 Note that a complete set of 36 clocks must be sent in order to clear the shift registers. When is powered ON, reset signal is generated internally to reset all registers and all latches. Then, the START bit and the first clock make it return to its normal operation. Figure 2 shows the pin-out of the package for. Figure 3 shows the pad-assignment of the bare chip for.the timing relationships between data, clock and DATA ENABLE is shown in Figure 4, with maximum clock frequency of 0.5 MHz assumed. When this driver is used for applications with lesser number of outputs, the current per output can be increased, or the part can be operated at higher than 1V (Vout). The following equation can be used for calculations. Tj = (Vout) (I LED ) (NO. of segments) (82 /W)+T A Where: Tj = junction temperature (150 max) Vout = the voltage at the LED driver outputs I LED = the LED current 82 /W = thermal resistance of the package T A = ambient temperature The above equation was used to plot Figure 6-8. CLOCK DATA DATA ENABLE 300 ns MIN Figure ns MIN LED Display Driver -7- Version:A.025

9 CLOCK START BIT 1 BIT 34 BIT 35 DATA LOAD (INTERNAL) RESET Figure 5 Input Data Format Output Current v.s. Number of Segments Vout = 1V Vout v.s. ILED 3.00 Ta = 85 Ta = 85 Tj = 150 (max.) SEGM Output Current (ma) Vout = 1.5V Vout = 2V Vout (Volt) SEGM 30 SEGM Figure 6 Number of Segments Figure 7 ILED (ma) Power dissipation v.s. Temperature Segments Vout = 1V 15 ma/segment Pdiss (W) Safe Operating Area Figure 8 Temp('C) LED Display Driver -8- Version:A.025

10 Typical Applications LED DISPLAY AM FM 35 DISPLAY DRIVER KEYBOARD ELECTRONIC TUNING CONTROLLER PLL SYNTHESIZER STATION DETECT, ETC Figure 9 Basic Electronically Tuned Radio System V LED =3.0V V LED =3.0V V LED V LED 9-12, , , , CLOCK IN DATA IN BRIGHTNESS CONTROL 100K TYP VDD Figure 10 Duplexing 8 Digits with One LED Display Driver -9- Version:A.025

11 Package Outline ( SSOP48 ) for -SS C H 45 E1 E 1 24 D GAUGE PLANE θ e b A1 A INCH L SYMBOL DIMENSION IN MM DIMENSION IN INCH MIN. NOM. MAX. MIN. NOM. MAX. A A b C e BASIC BASIC E E H L θ N D DIMENSION (IN INCH) JEDEC MO-118(AA) LED Display Driver -10- Version:A.025

12 The products listed herein are designed for ordinary electronic applications, such as electrical appliances, audio-visual equipment, communications devices and so on. Hence, it is advisable that the devices should not be used in medical instruments, surgical implants, aerospace machinery, nuclear power control systems, disaster/crime-prevention equipment and the like. Misusing those products may directly or indirectly endanger human life, or cause injury and property loss. Silicon Touch Technology, Inc. will not take any responsibilities regarding the misusage of the products mentioned above. Anyone who purchases any products described herein with the above-mentioned intention or with such misused applications should accept full responsibility and indemnify. Silicon Touch Technology, Inc. and its distributors and all their officers and employees shall defend jointly and severally against any and all claims and litigation and all damages, cost and expenses associated with such intention and manipulation. LED Display Driver -11- Version:A.025