OZ962 High-Efficiency Inverter Controller FEATURES GENERAL DESCRIPTION • The OZ962 is a unique high-efficiency, CCFL backlight controller. It generates symmetrical, near sinusoidal output voltage and current waveforms for driving a CCFL backlight. The OZ962 operates in a single, constant frequency, pulse-width-modulation (PWM) mode. Typical operating frequency ranges between 30 KHz to 100 KHz, depending on the CCFL and the transformer’s characteristics. • • • • • • • • Single-stage power conversion, input voltage range of 5V to 18V Reduces the number of components and board size by 30% compared with conventional design Supports both floating and grounded secondary designs 90% efficiency vs. typical 75% efficiency of conventional designs Internal open-lamp and short-circuit protections Wide dimming range Supports synchronization among multiple inverter modules Reliable 2 -winding transformer design, eliminates arcing problems Constant frequency, symmetrical, sinusoidal drive Operating in a PWM push-pull manner, the transformer in the OZ962 backlight inverter requires only one primary winding and one secondary winding, with the secondary winding requiring no fold-back treatment. The OZ962 is available in both 16-pin SOIC and TSSOP packages. It is specified over the commercial temperature range: 0 oC to +70 oC. ORDERING INFORMATION OZ962R - 16 lead TSSOP OZ962G - 16-pin plastic SOP TYPICAL APPLICATION CIRCUIT VDD (+12V) F1 1A Fast Fuse ENA + - C1 22u 25V GND R10 100 R5 10K CN1 U1 16 REF VDD OZ962G 2 15 RT OVP 14 3 NC CT 4 13 SCP CLK 5 12 ADJ ENA 6 11 FB NDR 7 10 CMP PDR 8 9 GND SST 3 C7 U2 1 R9 R1 220K 200K C9 .01u R2 10K C2 R3 5.1K C3 0.1u 330p R11 1M Q2 C8 0.22u * 33T 4 5,6 C5 220p R7 100K SI4559EY - * 2200T 68p 3KV C6 2.2u 50V 3.5W + R14 7,8 R6 30 1.0K 2 Q1 1 C4 0.1u R4 15K R8 0.5 R12 750 R13 100 Figure 1. Typical Floating Secondary Application Circuit 03/01/00 Copyright 1999 by O2Micro OZ962-SF-2.7 All Rights Reserved Page 1 U.S. Patent #5,619,402 OZ962 FUNCTIONAL BLOCK DIAGRAM Ct(14) Rt(15) Under Voltage Lockout OVP(2) RAMP OSC OVP Voltage Generator OVP NDR(11) Break Before Make OVP=Vref-(Vdd - 1)(12.5/150) D=1.1(OVP)/2.5 - 0.2 VDD(16) N-Clamp PDR(10) Band Gap Reference Vref (2.5V) OSC REF(1) S Q R Q P-Clamp RAMP 1/2F ADJ(5) Error Amp. 40k CLK(13) Ve Ve=Vcmp-2*(Vcmp-SST-Vgs) Vcmp 60k FB(6) 3V 30k 1k SST CMP(7) Dmax Clamp Vdd OVP 9k 3µ A 10µA ENA(12) SST SST(9) OVP 2.0v SCP & OVP inhibited during start-up 2µA ADJ OVP SCP UVL shut down latch SCP(4) Note: OVP – Over Voltage Protection SCP – Short-Circuit Protection UVL – Under Voltage Lockout Figure 2. Functional Block Diagram OZ962-SF-2.7 Page 2 GND(8) OZ962 PIN DESCRIPTION Names REF OVP Pin No. 1 2 I/O O I NC SCP ADJ FB CMP GND SST 3 4 5 6 7 8 9 I I I O GND I PDR NDR ENA CLK CT RT VDD 10 11 12 13 14 15 16 O O I O I/O I/O PWR Description Reference voltage output. Nominal voltage is 2.5 V. Over-voltage protection setting. Refer to formula for OVP in block diagram on page 2 of this document. No connection. Short-circuit protection input. Reference voltage input for dimming control. Current sense feedback. Compensation for the current sense feedback. Ground. Tsst ~ 0.2 Csst (Vdd - 5), where Csst is the soft start capacitor value in µF and Tsst value is in µs. Gate drive output for the P-MOSFET. Gate drive output for the N-MOSFET. Enable input, active high (Vth is about 1.7 V). Open-drain clock output. Timing capacitor. CT and RT set the clock frequency. Timing resistor. Supply voltage input. ABSOLUTE MAXIMUM RATINGS VDD GND Logic inputs Power dissipation 18 V +/- 0.3 V -0.3 V to VDD+0.3 V 800 mW at 25 oC Operating temp. Operating junction temp. Storage temp. 0 oC to 70 oC 150 oC -55 to 150 oC RECOMMENDED OPERATING RANGE VDD Fosc Rosc 5V to 18V 30 KHz to 100 KHz 50 k to 150 k OZ962-SF-2.7 Page 3 OZ962 FUNCTIONAL SPECIFICATIONS Parameter Symbol Test Conditions 5 V < VDD < 15 V Limits Unit Min Typ Max 2.37 2.50 2.63 Reference Voltage Nominal voltage Vref Iload = 0.25 mA, V VDD = 5 V Line regulation - 8 - mV/V Iload = 0.2 mA to 1.0 mA - 1 - mV/mA Ct = 220 pF, Rt = 120 k 48 53 58 KHz Ramp peak 2.45 2.55 2.65 V Ramp valley 0.40 0.45 0.50 V TA = 0 C to 70 C - - 200 ppm/ oC Input bias current V ADJ =V FB =2.0 V - 25 500 nA Input offset voltage V FB = 4.0 V - 5 10 mV Input voltage range 0 - VDD1.5 V Open loop voltage gain 50 60 - dB Unity gain bandwidth 1 1.5 - MHz Power supply rejection 50 60 - dB Positive-going threshold voltage - 3.8 4 V Negative-going threshold voltage 3.4 3.6 - V Load regulation Oscillator Initial accuracy fosc o Temp. stability o Error Amplifier Under-Voltage Lockout Supply IOFF VDD = 5.0 V - 25 120 µA IOFF VDD = 15 V - 25 120 µA Supply current - Enable High ION VDD = 5.0 V - 0.6 1.5 mA Supply current - Enable High ION VDD = 15 V - 0.6 1.5 mA V OH Isink = 10 mA, VDD0.3 VDD0.5 - V Supply current - Enable Low Adj, CT = Open Supply current - Enable Low Adj, CT = Open NDR output Output high voltage VDD < 7.8 V 7.0 8.0 9.0 V Output low voltage V OL VDD >7.8 V Isource = 10 mA - 0.3 0.8 V Output resistance ROUT VDD = 5.0 V - 50 80 Ω Output high voltage V OH Isink = 10 mA VDD0.6 VDD0.3 - V Output low voltage V OL Isource = 10 mA, 0.4 0.5 0.8 V VDD > 7.8 V - VDD6.0 VDD4.0 VDD = 5.0 V - 50 80 Ω PDR output VDD < 7.8 V Output resistance ROUT Break-Before-Make Qn off to Qp on delay THL 200 240 280 ns Qp off to Qn on delay TLH 220 260 300 ns OZ962-SF-2.7 Page 4 OZ962 PACKAGE INFORMATION A2 A1 A TSSOP-16 PACKAGE E E1 1 θ2 D R1 Gauge Plane b R e b c L c1 θ3 b1 DIM A A1 A2 L D E1 E R R1 b b1 c c1 L1 e θ1 θ2 θ3 OZ962-SF-2.7 INCHES MIN MAX 0.043 0.002 0.006 0.031 0.041 0.020 0.030 0.169 0.177 0.252BSC 0.004 0.004 0.007 0.012 0.007 0.010 0.004 0.008 0.004 0.006 0.039REF 0.026BSC 0° 8° 12°REF 12°REF θ1 L1 MILLIMETERS MIN MAX 1.20 0.05 0.15 0.80 1.05 0.45 0.75 4.90 5.10 4.30 4.50 6.40BSC 0.09 0.09 0.19 0.30 0.19 0.25 0.09 0.20 0.09 0.16 1.0REF 0.65BSC 0° 8° 12°REF 12°REF Page 5 OZ962 DIM E H SOP-16 PACKAGE 1 A A1 B C D E e H L α D INCHES MIN MAX 0.0532 0.0688 0.0040 0.0098 0.013 0.020 0.0075 0.0098 0.3859 0.3937 0.1497 0.1574 0.050 BCS. 0.2284 0.244 0 0.016 0.050 0° 8° MILLIMETERS MIN MAX 1.35 1.75 0.10 0.25 0.33 0.51 0.19 0.25 9.80 10.00 3.80 4.00 1.27 BCS. 5.80 6.20 0.40 0° 1.27 8° D A B e A1 C α L OZ962-SF-2.7 Page 6