DS3992Z-09P+R

DS3992 MAXIM | Alldatasheet

Document overview

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Technical content

Features

o Two-Channel CCFL Controller for Backlighting LCD Panels for PC Monitors and LCD-TVs o Minimal BOM Provides Low-Cost Inverter Solution o Per-Channel Lamp Fault Monitoring for Lamp- Open, Lamp Overcurrent, Failure to Strike, and Overvoltage Conditions o Accurate (±10%) On-Board Oscillator for Lamp Frequency (40kHz to 80kHz) o Accurate (±10%) On-Board Oscillator for DPWM Burst-Dimming Frequency (90Hz to 220Hz or 180Hz to 440Hz) o Device Supply Undervoltage Lockout o Inverter Supply Undervoltage Lockout o Burst-Dimming Soft-Start Minimizes Audible Transformer Noise o Strike Frequency Boost o 100% to < 10% Dimming Range o 4.5V to 5.5V Single-Supply Operation o -40°C to +85°C Temperature Range o 16-Pin SO Package (150 mils) DS3992 Two-Channel, Push-Pull CCFL Controller SO-150 TOP VIEW OVD2 LCM1 OVD1 GA2 VCC VCC GA1 GB1 POSC LOSC GB2 VCC GND SVM BRIGHT LCM2 DS3992 Pin Configuration Rev 0; 9/06 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. +Denotes lead-free package. T&R denotes tape-and-reel package.

Ordering Information

FREQUENCY RANGE BRIGHT POLARITY PIN-PACKAGE DS3992Z-09P+ -40°C to +85°C 90Hz to 220Hz Positive 16 SO-16 (150 mils) DS3992Z-09N+ -40°C to +85°C 90Hz to 220Hz Negative 16 SO-16 (150 mils) DS3992Z-18P+ -40°C to +85°C 180Hz to 440Hz Positive 16 SO-16 (150 mils) DS3992Z-18N+ -40°C to +85°C 180Hz to 440Hz Negative 16 SO-16 (150 mils) DS3992Z-09P+T&R -40°C to +85°C 90Hz to 220Hz Positive 16 SO-16 (150 mils) DS3992Z-09N+T&R -40°C to +85°C 90Hz to 220Hz Negative 16 SO-16 (150 mils) DS3992Z-18P+T&R -40°C to +85°C 180Hz to 440Hz Positive 16 SO-16 (150 mils) DS3992Z-18N+T&R -40°C to +85°C 180Hz to 440Hz Negative 16 SO-16 (150 mils) Typical Operating Circuits appear at end of data sheet.

Two-Channel, Push-Pull CCFL Controller ABSOLUTE MAXIMUM RATINGS RECOMMENDED OPERATING CONDITIONS (TA = -40°C to +85°C.) Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specificatio ns is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Voltage on Any Leads Other PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage V CC (Note 1) 4.5 5.5 V SVM Voltage Range V SVM -0.3 VCC + 0.3 V BRIGHT Voltage Range V BRIGHT -0.3 VCC + 0.3 V LCM Voltage Range V LCM (Note 2) -0.3 VCC + 0.3 V OVD Voltage Range V OVD (Note 2) -0.3 VCC + 0.3 V Gate-Driver Output Charge Loading Q G 20 nC

ELECTRICAL CHARACTERISTICS

(VCC = +4.5V to +5.5V, TA = -40°C to +85°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Current I CC GA, GB loaded with 600pF, 2 channels active 81 6 m A Low-Level Output Voltage (GA, GB) V OL IOL = 4mA 0.4 V High-Level Output Voltage (GA, GB) V OH1 IOH1 = -1mA VCC - 0.4 V UVLO Threshold: VCC Rising V UVLOR 4.3 V UVLO Threshold: VCC Falling V UVLOF 3.7 V UVLO Hysteresis V UVLOH 100 mV SVM Falling-Edge Threshold V SVM 1.9 2.0 2.1 V SVM Hysteresis V SVMH 150 mV LCM and OVD DC Bias Voltage V DCB 1.35 V LCM and OVD Input Resistance R DCB 50 k Ω Lamp-Off Threshold V LOT (Note 3) 1.65 1.75 1.85 V Lamp Over Current V LOC (Note 3) 3.15 3.35 3.55 V Lamp Regulation Threshold V LRT (Note 3) 2.25 2.35 2.45 V OVD Threshold V OVDT (Note 3) 2.25 2.35 2.45 V Lamp Frequency Range f LFS:OSC 40 80 kHz

Two-Channel, Push-Pull CCFL Controller Note 2: During fault conditions, the AC-coupled feedback values are allowed to be below the Absolute Maximum Rating of the LCM or OVD pin for up to 1s. Note 3: Voltage with respect to VDCB. ELECTRICAL CHARACTERISTICS (continued) (VCC = +4.5V to +5.5V, TA = -40°C to +85°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Lamp Frequency Tolerance f LFS:TOL LOSC resistor ±2% over temperature -10 +10 % DS3992Z-09P/N 90 220DPWM Frequency Range f DSR:OSC DS3992Z-18P/N 180 440 Hz DPWM Frequency Tolerance f DSR:TOL POSC resistor ±2% over temperature -10 +10 % DS3992Z-09P / DS3992Z-18P 0.5BRIGHT Voltage: Minimum Brightness VBMIN DS3992Z-09N / DS3992Z-18N 2.0 V DS3992Z-09P / DS3992Z-18P 2.0BRIGHT Voltage: Maximum Brightness VBMAX DS3992Z-09N / DS3992Z-18N 0.5 V Gate-Driver Output Rise/Fall Time t R / tF CL = 600pF 50 100 ns GAn and GBn Duty Cycle 44 % Strike Time t STRIKE 500 ms Typical Operating Characteristics (VCC = 5.0V, TA = +25°C, unless otherwise noted.) 4.0 5.0 4.5 6.0 5.5 7.0 6.5 7.5 8.5 8.0 9.0 vs. SUPPLY VOLTAGE DS3992 toc01 SUPPLY VOLTAGE (V) SUPPLY CURRENT (mA) DPWM = 10% DPWM = 50% DPWM = 100% SVM ≤ 2V GATE QC = 3.5nC fLFOSC = 64kHz 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 -40.0 22.5 85.0 ACTIVE SUPPLY CURRENT vs. TEMPERATURE DS3992 toc02 TEMPERATURE (°C) SUPPLY CURRENT (mA) VCC = 5.5V GATE QC = 3.5nC fLFOSC = 64kHz DPWM = 100% VCC = 5.0V VCC = 4.5V -1.0 -0.4 -0.6 -0.8 -0.2 0.2 0.4 0.6 0.8 1.0 -40.0 22.5 85.0 INTERNAL FREQUENCY CHANGE vs. TEMPERATURE DS3992 toc03 TEMPERATURE (°C) FREQUENCY CHANGE (%) DPWM FREQUENCY LAMP FREQUENCY

Two-Channel, Push-Pull CCFL Controller Typical Operating Characteristics (continued) (VCC = 5.0V, TA = +25°C, unless otherwise noted.) TYPICAL OPERATION AT 16V DS3992 toc0410μs 5.0V GA 10μs 5.0V GB 10μs 2.0V LCM 10μs 2.0V OVD BURST DIMMING AT 150Hz AND 10% DS3992 toc051ms 5.0V GA 1ms 5.0V GB 1ms 2.0V LCM 1ms 2.0V OVD TYPICAL STARTUP WITH SVM DS3992 toc06 2ms 2.0V SVM 2ms 5.0V GB 2ms 2.0V LCM 2ms 2.0V OVD BURST DIMMING AT 150Hz AND 50% DS3992 toc071ms 5.0V GA 1ms 5.0V GB 1ms 2.0V LCM 1ms 2.0V OVD SOFT-START AT VINV = 16V DS3984 toc0850μs 5.0V GA 50μs 5.0V GB 50μs 2.0V LCM 50μs 2.0V OVD LAMP STRIKE—EXPANDED VIEW DS3992 toc091ms 5.0V GA 1ms 5.0V GB 1ms 2.0V LCM 1ms 2.0V OVD LAMP OUT (LAMP OPENED), AUTORETRY DISABLED DS3992 toc100.25 5.0V GA 0.25 5.0V GB 0.25 2.00V LCM 0.25 2.00V OVD LAMP OPENED

Two-Channel, Push-Pull CCFL Controller Pin Description PIN NUMBER NAME I/O FUNCTION 1 LOSC ⎯ Lamp Oscillator Resistor Adjust. A resistor (RLOSC) to ground on this pin sets the frequency of the lamp oscillator (fLFS:OSC). [RLOSC x fLFS:OSC = 1.6E9].

2 POSC ⎯

Burst Dimming DPWM Oscillator Resistor Adjust. A resistor (RPOSC) to ground on this lead sets the frequency (fDSR:OSC) of the burst-dimming DPWM oscillator. [RPOSC x fDSR:OSC = 4.0E6 for DS3992Z-09P and DS3992Z-09N and RPOSC x fDSR:OSC = 8.0E6 for DS3992Z-18P and DS3992Z-18N]. 3 BRIGHT I Lamp Brightness Control. An analog voltage at this input controls the lamp brightness. See Table 1 for details.

4 SVM I

Supply Voltage Monitor. The DC inverter supply voltage is monitored by an external resistor divider. The resistor-divider should be set such that it provides 2V at this pin for the minimum allowable range of the DC inverter supply. Pulling this input below 2V will turn the lamps off and reset the controller. Connect to VCC if not used. 5 GA1 O MOSFET Gate Drive A for Channel 1. Connect directly to the gate of a logic-level mode n-channel MOSFET. 6 GB1 O MOSFET Gate Drive B for Channel 1. Connect directly to the gate of a logic-level mode n-channel MOSFET. 7 LCM1 I Lamp Current Monitor Input for Channel 1. Lamp current is monitored by a resistor placed in series with the low-voltage side of the lamp. 8 OVD1 I Over Voltage Detection for Channel 1. Lamp voltage is monitored by a capacitor divider placed on the high-voltage side of the lamp.

9 GND ⎯ Signal Ground

10 V CC ⎯ Supply. 4.5V to 5.5V. 11 GA2 O MOSFET Gate Drive A for Channel 2. Connect directly to the gate of a logic-level mode n-channel MOSFET. 12 GB2 O MOSFET Gate Drive B for Channel 2. Connect directly to the gate of a logic-level mode n-channel MOSFET. 13 LCM2 I Lamp Current Monitor Input for Channel 2. Lamp current is monitored by a resistor placed in series with the low-voltage side of the lamp. 14 OVD2 I Overvoltage Detection for Channel 2. Lamp voltage is monitored by a capacitor divider placed on the high-voltage side of the lamp. 15 V CC ⎯ Supply. 4.5V to 5.5V. 16 V CC ⎯ Supply. 4.5V to 5.5V.

Figure 1. DS3992 Functional Diagram

ly control the CCFL current. mine the duty cycle for the MOSFET gates. Circuits section for more information. cussed on the following pages of this data sheet. lamp frequency (40kHz to 80kHz) as shown in Figure 3.

64 LAMP CYCLE

Figure 2. DS3992 Per Channel Logic Diagram Figure 3. Digital-PWM Dimming and Soft-Start

between the minimum and 100%. returned to the normal lamp frequency. -18N/P version (180Hz to 440Hz). the lamp frequency K value regardless of the frequency. can be disabled by connecting the SVM pin to GND. point. This monitor cannot be disabled by any means. monitor (SVM) input is > 2V. Table 1. BRIGHT Analog Dimming Input Configuration

moves to the fault handling stage. CC drops below the UVLO threshold.

• The SVM input drops below 2.0V. Applications Information Component Selection External component selection has a large impact on the overall system performance and cost. The two most important external components are the transformers and n-channel MOSFETs. The transformer should be able to operate in the 40kHz to 80kHz frequency range of the DS3992, and the turns ratio should be selected so the MOSFET drivers run at 28% to 35% duty cycle during steady-state operation. The transformer must be able to withstand the high open-circuit voltage that will be used to strike the lamp. Additionally, its primary/secondary resistance and inductance characteristics must be considered because they contribute significantly to determining the YES MOSFET GATE DRIVERS ENABLED RUN LAMP STAGE DEVICE AND INVERTER SUPPLIES AT PROPER LEVELS? FAULT STATE [MUST POWER CYCLE THE DS3992 OR TAKE SVM BELOW 2V TO RESET THE CCFL CONTROLLER] LAMP OVERCURRENT [INSTANTANEOUS] STRIKE LAMP [RAMP AND REGULATE TO OVD THRESHOLD] LAMP STRIKE TIMEOUT [65536 LAMP CYCLES] RUN LAMP [REGULATE LAMP CURRENT BOUNDED BY LAMP VOLTAGE] LAMP-OUT TIMEOUT [65,536 LAMP CYCLES] OVERVOLTAGE [64 LAMP CYCLES] IF LINE REGULATION THRESHOLD IS MET

Figure 4. Fault-Handling Flowchart

for a 12V inverter supply, 438mm x 2.2mm lamp design. channel MOSFETs now available in SO-8 packages. Table 2. Transformer Specifications (as Used in the Typical Operating Circuit) Note 1: Primary should be Bifilar wound with center tap connection. Note 2: Turns ratio is defined as secondary winding divided by the sum of both primary windings. Note 3: 40:1 is the nominal turns ratio for driving a 438mm x 2.2mm lamp with a 12V supply. Refer to AN3375 for more information.

Two-Channel, Push-Pull CCFL Controller INVERTER SUPPLY VOLTAGE GB1 OVD1 LCM1 SVM GA1 CCFL LAMP DUAL POWER MOSFET RLCM TRANSFORMER OVERVOLTAGE DETECTION LAMP CURRENT MONITOR VCC DEVICE SUPPLY VOLTAGE (5V ±10%) VCC VCC BRIGHT ANALOG LAMP BRIGHTNESS CONTROL LOSC POSC RESISTOR SET LAMP FREQUENCY RESISTOR SET BURST DIMMING FREQUENCY GB2 OVD2 LCM2 GND GA2 CCFL LAMP DUAL POWER MOSFET RLCM TRANSFORMER OVERVOLTAGE DETECTION LAMP CURRENT MONITOR DS3992 RLCM ILAMP(RMS 2 x Typical Operating Circuits Single Per Channel Operating Circuit

Two-Channel, Push-Pull CCFL Controller INVERTER SUPPLY VOLTAGE ON = OPEN OFF/RESET = CLOSED GB OVD LCM SVM GA CCFL LAMP A CCFL LAMP B CCFL LAMP C DUAL N-CHANNEL POWER MOSFET 2N3904 +5V

1 OF 2 CHANNELS

V CC DEVICE SUPPLY VOLTAGE (5V ±10%) VCC VCC BRIGHT ANALOG LAMP BRIGHTNESS CONTROL LOSC POSC RESISTOR SET LAMP FREQUENCY RESISTOR SET BURST DIMMING FREQUENCY GND DS3992 2N3904 +5V 2N3904 +5V Typical Operating Circuits (continued) Multi-Lamp Per Channel Operating Circuit

Two-Channel, Push-Pull CCFL Controller Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circu it patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 13 © 2006 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc. is a registered trademark of Dallas Semiconductor Corporation. Springer Power-Supply Decoupling To achieve best results, it is highly recommended that a decoupling capacitor be used on pin 10, the IC power- supply pin. Pins 15 and 16, also V CC pins, do require connection to supply voltage, but do not require any additional decoupling. Typical values of decoupling capacitors are 0.01µF or 0.1µF. Use a high-quality, ceramic, surface-mount capacitor, and mount it as close as possible to the V CC and GND pins of the IC to minimize lead inductance. Chip Topology TRANSISTOR COUNT: 53,000 SUBSTRATE CONNECTED TO GROUND

Package Information

For the latest package outline information, go to www.maxim-ic.com/DallasPackInfo.