BU2872AK

Standard ICs FL tube driver BU2872AK The BU2872AK is a driver IC for the FL display unit. It has a total of 22 high withstanding voltage output pins, and supports displays ranging from 11-segment 11-character displays to 16-segment 4-character displays. A key scan function, LED drive output, and a general-purpose input pin make this IC ideal for use in the front panels of VTRs and other equipment. A serial interface enables control of all functions through a microcomputer. •Applications VCRs •Features 1) High withstanding voltage output. 2) Display modes: 11S × 11G ~16S × 4G 3) Variable display luminance (7 steps). 4) 3-wire serial interface. 5) Key scanning function (6 × 4). 6) Internal pull-down resistance (high withstanding voltage output). 7) QFP 44-pin package. •Block diagram OSC SCK VDD G1 GRID Driver 16bit × 11word K4 KEY DATA latch (4 × 6) K1 Display DATA RAM L4 LED Driver 8bit shift - REG. VSS 16bit latch SO CS SI OSC L1 CONTROL LOGIC SW4 4bit data SW1 G6 SEGMENT Driver S / G Driver G11 / S12 G7 / S16 S11 S1 VEE 1 Standard ICs BU2872AK •Pin descriptions Pin No. 14, 38 44 7, 43 6 5 8 9 15 ~ 25 27 37 ~ 32 Pin VDD OSC VSS SI SO SCK CS S1 ~ S11 VEE G1 ~ G6 Name Power supply pin 1 Oscillation pin GND pin Serial data input Serial data output Serial clock input Serial chip select High withstanding voltage output pin for segment Power supply pin 2 High withstanding voltage output pin for grid High withstanding voltage output pin for segment / grid Output pin for LED Key data input pin General-purpose input pin I/O I I/O I I O I I O I O O O I I Function Connected to the power supply of the system Connected to the oscillation capacitor Connected to the ground of the system Serial data input starting from MSB Serial data output starting from MSB Serial data read at rising edge Serial initialization at "L", effective at "H" Output pin for segment Output: Pch open drain + pull-down resistance Pull-down resistance connection for FLP driver Output pin for grid Output: Pch open drain + pull-down resistance Segment / grid output selectable pin Output: Pch open drain + pull-down resistance Output pin for LED; output is CMOS output Data input pin for key scanning General-purpose input pin Input data sent to microcomputer in serial format 26, 28 ~ 31 S12 / G11 ~ S16 / G7 42 ~ 39 10 ~ 13 1~4 L1 ~ L4 K1 ~ K4 SW1 ~ SW4 •Absolute maximum ratings (Ta = 25°C, V Parameter Applied voltage 1 Applied voltage 2 Input voltage Power dissipation Operating temperature Storage temperature Symbol VDD VEE VIN Pd Topr Tstg SS = 0V) Limits – 0.3 ~ + 7.0 VDD + 0.3 ~ VDD – 35 – 0.3 ~ VDD + 0.3 850∗ – 25 ~ + 75 – 55 ~ + 125 Unit V V V mW °C °C Note) Operation is not guaranteed at these values. ∗ When mounted on a 70mm × 70mm × 1.6mm glass epoxy board Power dissipation is reduced by 8.5mW for each increase in Ta of 1°C over 25°C. •Recommended operating conditions (Ta = 25°C, V Parameter Operating power supply voltage 1 Operating power supply voltage 2 Symbol VDD VEE SS = 0V) Typ. 5.0 Max. 5.5 Unit V V Min. 4.5 VDD – 32 VDD – 30 VDD – 0 2 Standard ICs BU2872AK DD •Electrical characteristics (unless otherwise noted, Ta = 25°C, V Parameter Supply current Input threshold voltage Input current Oscillation frequency Segment output current Grid output current Off level leakage current Output pull-down resistance LED output high level voltage LED output low level voltage 〈Serial transfer〉 Input data hold Input data setup Output data delay Input clock cycle Input clock "H" width TSH TSS TD TSCYC T 0.16 0.16 — 0.5 40 — — — — — — — 0.3 — 60 µs µs µs µs % Symbol IDD VIN IIN FOSC IOseg IOgrd IOFF RD VOH VOL Min. — 1.5 — 130 7 20 — 15 4.0 — Typ. — — — 200 — — — 31 — — Max. 5 3.5 10 300 — — 10 60 — 1.0 Unit mA V µA kHz mA mA µA kΩ V V = 5V, VSS = 0V, VDD-VEE = 30V) Conditions Measurement circuit Fig.1 Fig.5 Fig.2 Fig.4 – 2V ∗2 Fig.2 Fig.2 Fig.2 Fig.2 Fig.3 Fig.3 – 2V ∗2 Pin 44 external 1000 pF, when oscillated Pins 1 to 4, 6, 8, 9 to 13 Pins 1 to 4, 6, 8, 9 to 13 Pin 44 external 1000 pF Pins 15 to 26, 28 to 31 VO = VDD Pins 26, 28 to 37 VO = VDD Pins 15 to 26, 28 to 37 VO = VDD – VEE Pins 15 to 26, 28 to 37 Pins 39 to 42 IO = 1mA Pins 39 to 42 IO = – 10mA — — — — Input clock cycle at minimum value — — — — — ∗2 Each of the high withstanding voltage output pins, pins 26 and 28 to 31, outputs the segment output current when set to the segment output and the grid current when set to the grid output. •Measurement circuits A VEE 1000p OSC VSS VSS n VDD VEE VDD n = Test pin A V VSS n V I VEE VDD n = Test pin Fig.1 Fig.2 Fig.3 VEE VDD G1 VSS Monitor VEE VDD 1000p OSC VSS Fig.4 Fig.5 3 Standard ICs “H” SEGMENT OUTPUT CURRENT : IOHseg (mA) BU2872AK •Electrical characteristic curves “H” GRID OUTPUT CURRENT : IOHgrd (mA) 3.8 3.7 3.6 3.5 3.4 3.3 3.2 50 SUPPLY CURRENT : IDD (mA) 45 40 13 12.8 12.6 12.4 12.2 12 11.8 11.6 11.4 11.2 11 35 30 – 25 25 TEMPERATURE : Ta (°C) 75 25 – 25 25 TEMPERATURE : Ta (°C) 75 – 25 25 TEMPERATURE : Ta (°C) 75 Fig.6 Supply current temperature characteristics Fig.7 “H” grid output current temperature characteristics Fig.8 “H” segment output current temperature characteristics “L” LED OUTPUT CURRENT : IOLLED (mA) 0.76 0.74 0.72 0.7 0.68 0.66 0.64 0.62 0.6 0.58 0.56 0.54 – 25 25 TEMPERATURE : Ta (°C) 75 Fig. 9 “L” LED output current temperature characteristics •External dimensions (Units: mm) 14.0 ± 0.3 33 14.0 ± 0.3 10.0 ± 0.2 34 10.0 ± 0.2 23 22 44 1 11 12 2.15 ± 0.1 0.05 0.8 0.35 ± 0.1 0.15 QFP44 4 1.2 0.15 ± 0.1