Standard ICs EL driver for portable sets BA3899F The BA3899F is an IC developed for EL drive applications. It uses a more compact interface than transformer systems, and is ideal for use in thin sets. Applications •Pagers, electronic notebooks and other portable devices •1)Features Drive oscillation frequency can be set using external capacitance. 2) Equipped with standby control pin. •Absolute maximum ratings (Ta = 25°C) Parameter Power supply voltage Symbol Limits Unit VCC 8.0 V mW Pd 450∗ Operating temperature Topr – 10 ~ + 60 °C Storage temperature Tstg – 55 ~ + 125 °C Maximum applied voltage VST Power dissipation 8.0 V ∗ Reduced by 4.5mW for each increase in Ta of 1°C over 25°C. •Recommended operating conditions (Ta = 25°C) Parameter Symbol Min. Typ. Max. Unit VCC 1.0 5.0 7.0 V Power supply voltage •Block diagram SW1 SW2 VCC STBY 8 7 6 5 STBY RSW2 OSC1 OSC2 1 2 3 4 GND N.C. C1 C2 1 Standard ICs BA3899F •Pin descriptions Pin No. Pin name I/O Pin voltage Internal equivalent circuit 1 GND I — — 2 N.C. — — — Function GND pin — VCC 3 C1 I/O — 1k OSC1 oscillator circuit; external capacitor pin 200Ω OSC2 oscillator circuit; external capacitor pin C1 GND VCC 4 C2 I/O — C2 GND 1k Standby control pin (HIGH state: standby cancelled) 50k STBY 5 STBY I 0 䊊When applying resistance, etc. to the STBY pin, be careful not to exceed the threshold values. 200k GND 6 VCC I — — VCC input pin VCC 50k 7 SW2 O SW2 switching output pin — X1 X20 SW2 500Ω GND VCC 8 SW1 O X1 — GND 2 X5 SW1 SW1 switching output pin Standard ICs BA3899F •Electrical characteristics (unless otherwise noted, Ta = 25°C, V CC Parameter Symbol Min. Typ. Supply current ICC 3.0 C1 pin oscillation frequency fSW1 75 C2 pin oscillation frequency = 5.0V, C1 = 0.033µF, C2 = 1500pF) Max. Unit 4.6 6.2 mA 95 120 Hz Conditions When used as stand-alone unit — fSW2 17 23 29 kHz — ISW1SO 100 140 180 µA VC1 = 1.0V, VC2 = 0.05V, VSW1 = 0V Sink current ISW1SI – 40 — — µA VC1 = 0.05V, VC2 = 0.05V, VSW1 = 1.0V Source current ISW2SO 3.2 4.4 6.1 mA VC1 = 0.05V, VC2 = 0.05V, VSW2 = 0V Pull-down resistance RSW2 400 500 600 Ω Standby pin control Operating voltage condition Non-operating VSTON 1.0 — — V — VSTOFF — — 0.3 V — IQ (ST) — 0 2.0 µA — SW1 SW2 Source current Quiescent current in standby state Vst = 0.35V, VSW2 = 0.3V •Measurement circuit fSW1 fSW2 Counter Counter VSW1 VSW2 VCC A IQ ISW2 8 VSTBY A A ISW1 7 6 5 STBY RSW2 1 2 VC1 OSC1 OSC2 3 4 0.033µF ± 1% VC2 1500pF ± 1% Fig.1 3 Standard ICs BA3899F •Application example D1 EL 16000pF R1 ROHM: 1SS376 ∗ L1 1.5mH (TOKO: D73LC) 2k Q2 Q1 + SANYO: 2SC3645T 2.2µF 100k VCC = 5V ROHM: 2SC4061KP 8 7 SW1 6 SW2 VCC 5 STBY STBY RSW2 RX 300k OSC1 1 GND 2 N.C. 3 OSC2 C1 C1 8200pF ± 10% 4 C2 C2 1500pF ± 10% Fig. 2 ∗ Because of the characteristics of the EL element, continuous application of particularly high DC power supply voltage can shorten the lifetime of the element. To avoid this, we recommend inserting a switch in the power supply line. 4 Standard ICs BA3899F D1 ROHM: 1SS376 EL 5000pF R1 L1 1mH (TOKO: 43FS) or (TDK: NL453232) 4.7k Q2 Q1 + SANYO: 2SC3143K5 2.2µF VCC = 1.5V ROHM: 2SC4061KP 8 7 SW1 6 SW2 VCC 5 STBY VSTBY = 1.5V Hi: act STBY RSW2 OSC2 OSC1 1 GND 2 N.C. 3 C1 C1 0.033µF ± 10% 4 C2 C2 1500pF ± 10% Fig. 3 5 Standard ICs BA3899F notes •(1)Operation EL drive output (4) Q1, Q2, and D1 The VO (Max.) shown in Figure 4 is applied to the output VO, so if using any transistor other than that recommended, caution is required concerning the pressure withstand value. Also, Q2 must have characteristics which allow it to keep pace with the switching speed of fSW2. As shown in Figure 4, the EL drive output consists of charging (rise in voltage caused by switching) and discharging waveforms. The switching frequency is determined by fSW2 and the charging and discharging timing by fSW1. tSW1 (fSW1) VO (Max.) t2 Discharge t1 Charge Fig.4 (2) Setting fSW1 The oscillation frequency is determined by charging and discharging of the external capacitance of the C1 pin. The value for C1 should be set based on the following equation. C1 = 1 VC1 × ( 1 + 1 ) I2 I1 1 = (3.14E – 6) × fSW1 × 1 (5) RX (resistor for adjusting light volume) With a configuration like that shown in Figure 5, the volume of light can be adjusted. However, RX should be set so that IX satisfies the following condition. Ix ( = fSW1 (VCC = 5V) If IX > 40µA, LSI dispersion, temperature fluctuation, and other elements can cause oscillation of the C2 pin to stop. Be sure the above condition is satisfied. The recommended setting range for fSW1 is 40Hz to 800Hz. However, the VO (Max.) shown in Figure 4 is determined by fSW1, so caution is required concerning the pressure withstand values of Q1, Q2, and D1. (3) fSW2 fSW2 is the switching pressure rise frequency, and is determined by the external capacitance of the C2 pin. This value (1500pF) is determined by the inductance value and the Q2 transistor capability. When changing this value, the drive capability of Q2 must be taken into consideration in order to avoid the possibility of malfunction. 6 Vx – 0.2V ) < 40µA Rx C2 4 Rx Vx Ix 1500pF Fig.5 Standard ICs BA3899F •Electrical characteristic curves C1 = 0.033µF C2 = 1500pF VST = 5V Rx = ∞ 9 8 7 OSCILLATION FREQUENCY: fSW (Hz) QUIESCENT CURRENT: ICC (mA) 10 75°C 6 5 4 – 25°C 3 25°C 2 1 fSW1 75°C – 25°C 10k 25°C C1 = 0.033µF C2 = 1500pF Rx = ∞ 1k fSW2 75°C 100 – 25°C 25°C 0 0 1 2 3 4 5 6 7 8 9 10 0 1 2 INPUT VOLTAGE: VCC (V) Fig. 6 Supply current (when used as stand-alone unit) vs. power supply voltage 5 6 7 8 3.0 75°C SW1 SINK CURRENT: ISW1SI (%) SW1 SOURCE CURRENT: ISWISO (µA) 4 Fig. 7 Oscillation frequency of C1 and C2 pins vs. power supply voltage 250 200 25°C 150 – 25°C 100 50 VC1 = 1.0V VSW1 = 0V 0 0 1 2 3 4 5 6 7 8 9 VC1 = 0V VSW1 = 1.0V VST = 5V 2.0 75°C 25°C 1.0 – 25°C 10 0 10 0 1 2 INPUT VOLTAGE: VCC (V) VC1 = 1.0V VSW1 = 0V VST = 5V 9 8 7 75°C 6 5 4 – 25°C 3 25°C 2 1 0 0 1 2 3 4 5 6 7 8 4 5 6 7 8 9 10 Fig. 9 SW1 source current vs. power supply voltage 9 INPUT VOLTAGE: VCC (V) Fig. 10 SW2 source current vs. power supply voltage 10 SW2 PULL-DOWN RESISTANCE: RSW2 (Ω) 10 3 INPUT VOLTAGE: VCC (V) Fig. 8 SW1 sink current vs. power supply voltage SW2 SOURCE CURRENT: ISW2SO (mA) 3 INPUT VOLTAGE: VCC (V) 1000 VCC = 5V VSW2 = 0.2V VST = 0V 900 800 700 75°C 600 500 400 – 25°C 25°C 300 200 100 0 0 1 2 3 4 5 6 7 8 9 10 INPUT VOLTAGE: VCC (V) Fig. 11 SW2 pull-down resistance vs. power supply voltage 7 Standard ICs BA3899F •External dimensions (Units: mm) 1 4 0.11 1.27 0.15 ± 0.1 4.4 ± 0.2 5 1.5 ± 0.1 6.2 ± 0.3 5.0 ± 0.2 8 0.4 ± 0.1 0.3Min. 0.15 SOP8 8