TL496C, TL496Y 9-V POWER-SUPPLY CONTROLLERS SLVS012B – AUGUST 1978 – REVISED AUGUST 1995 • • • • • D OR P PACKAGE (TOP VIEW) Internal Step-Up Switching Regulator Fixed 9-V Output Charges Battery Source During Transformer-Coupled-Input Operation Minimum External Components Required (1 Inductor, 1 Capacitor, 1 Diode) 1- or 2-Cell-Input Operation FEEDBACK 2C INPUT 1C INPUT T INPUT 1 8 2 7 3 6 4 5 OUTPUT GND SW GND Terminals 5 and 7 are connected together internally. description The TL496C power-supply control circuit is designed to provide a 9-V regulated supply from a variety of input sources. Operable from a 1- or 2-cell battery input, the TL496C performs as a switching regulator with the addition of a single inductor and filter capacitor. When ac coupled with a step-down transformer, the TL496C operates as a series regulator to maintain the regulated output voltage and, with the addition of a single catch diode, time shares to recharge the input batteries. The design of the TL496C allows minimal supply current drain during standby operation (125 µA typical). With most battery sources, this allows a constant bias to be maintained on the power supply. This makes power instantly available to the system, thus eliminating power-up sequencing problems. AVAILABLE OPTIONS PACKAGED DEVICES TA SURFACE MOUNT (D) PLASTIC DIP (P) CHIP FORM (Y) 0°C to 70°C TL496CD TL496CP TL496Y functional block diagram T INPUT 4 9-V Series Regulator 8 1 6 2C INPUT 1C INPUT 2 3 OUTPUT FEEDBACK SW Switching Voltage Regulator Control 5 GND See Note 1 7 GND NOTE 1: Terminals 5 and 7, though connected together internally, must both be terminated to ground to ensure proper circuit operation. Copyright 1995, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 4–1 TL496C, TL496Y 9-VOLT POWER-SUPPLY CONTROLLERS SLVS012B – AUGUST 1978 – REVISED AUGUST 1995 TL496Y chip information This chip, when properly assembled, displays characteristics similar to the TL496C. Thermal compression or ultrasonic bonding may be used on the doped aluminum bonding pads. The chips may be mounted with conductive epoxy or a gold-silicon preform. BONDING PAD ASSIGNMENTS (4) (3) (5) CHIP THICKNESS: 15 MILS TYPICAL BONDING PADS: 4 × 4 MILS MINIMUM TJmax= 150°C TOLERANCES ARE ± 10% ALL DIMENSIONS ARE IN MILS 68 (6) (7) (8) (1) (2) 74 FEEDBACK 2C INPUT 1C INPUT T INPUT 4–2 (1) (8) (2) (7) TL496Y (3) (6) (4) (5) OUTPUT GND SW GND POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL496C, TL496Y 9-VOLT POWER-SUPPLY CONTOLLERS SLVS012B – AUGUST 1978 – REVISED AUGUST 1995 absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† Input voltage, VI: 2C INPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5 V 1C INPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 V T INPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 V Output voltage, VO (SW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 V Diode reverse voltage (OUTPUT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 V Switch current (SW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 A Diode current (OUTPUT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 A Continuous total power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Dissipation Rating Table Operating free-air temperature range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 65°C to 150°C Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°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 under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. DISSIPATION RATING TABLE PACKAGE TA ≤ 25°C POWER RATING DERATING FACTOR TA = 70°C POWER RATING D 725 mW 5.8 mW/°C 464 mW P 1000 mW 8.0 mW/°C 640 mW recommended operating conditions MIN MAX Input voltage, one-cell operation (2C and 1C INPUTS to ground) 1.1 1.5 V Input voltage, two-cell operation (2C INPUT to ground) 2.3 3 V VO + 2 20 V Input voltage, one-cell or two-cell operation (T INPUT to ground) POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 UNIT 4–3 TL496C, TL496Y 9-VOLT POWER-SUPPLY CONTROLLERS SLVS012B – AUGUST 1978 – REVISED AUGUST 1995 electrical characteristics over recommended operating conditions, TA = 25°C (unless otherwise noted) series regulator section (T INPUT) PARAMETER Dropout voltage TEST CONDITIONS VI = 5 V, Regulated output voltage Standby current, T INPUT Reverse current through T INPUT MIN IO = – 50 mA TYP MAX 1.5 2 VI = 20 V V, IO = – 50 µA IO = – 80 mA 9.5 10.1 11.2 9 10 11 VI = 20 V, FEEDBACK shorted to OUTPUT IO = – 50 µA IO = – 80 mA 8.5 9 9.7 6.7 8.6 VI = 20 V, VI = –1.5 V, UNIT V V 9.5 OUTPUT = 12 V 400 µA 1 mA into OUTPUT – 25 µA TYP MAX UNIT 0.35 0.6 output switch PARAMETER VCE(sat) Collector-emitter saturation voltage TEST CONDITIONS 800 mA into SW, MIN 2C INPUT = 2.25 V V diode (SW to OUTPUT) PARAMETER VF IR Forward voltage Reverse current through SW TEST CONDITIONS IF = 1.5 A SW at 0 V, MIN TYP MAX 1.6 2.5 V – 20 µA 1 mA into OUTPUT UNIT control section PARAMETER TEST CONDITIONS MIN TYP MAX UNIT 60 100 mA µA On-state current (2C INPUT) FEEDBACK and OUTPUT = 0 V, 2C INPUT = 3 V Standby current (FEEDBACK) FEEDBACK = 8.65 V, 2C INPUT and SW = 3 V 40 Standby current (2C INPUT and SW) FEEDBACK = 8.65 V, 2C INPUT and SW = 3 V 400 Start-up current (current into SW to initiate cycle) FEEDBACK, 2C INPUT, SW, and OUTPUT = 2.25 V 4–4 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 16 µA mA TL496C, TL496Y 9-VOLT POWER-SUPPLY CONTOLLERS SLVS012B – AUGUST 1978 – REVISED AUGUST 1995 APPLICATION INFORMATION L 3 T1 2 AC INPUT CIRCUIT COMPONENT INFORMATION D1: 1N4001 CO: 330 µF to 470 µF, 10 V, electrolytic L: 40 µH to 50 µH, Q ≈ 3, R < 0.15 Ω T1: Vsec = 6.8 V RMS typ, Rsec = 11 Ω typ 6 1C INPUT 2C INPUT SW OUTPUT 8 OUTPUT TL496C BATT 4 1 T INPUT FEEDBACK GND GND 7 D1 CO 5 GND Figure 1. One-Cell Operation L 3 T1 2 AC INPUT 1C INPUT 2C INPUT CIRCUIT COMPONENT INFORMATION D1: 1N4001 CO: 330 µF to 470 µF, 10 V, electrolytic L: 40 µH to 50 µH, Q ≈ 3, R < 0.15 Ω T1: Vsec = 6.8 V RMS typ, Rsec = 11 Ω typ 6 SW OUTPUT 8 OUTPUT TL496C 4 7 D1 1 T INPUT FEEDBACK GND GND CO 5 BATT GND Figure 2. Two-Cell Operation electrical characteristics for one- and two-cell input operations ONE-CELL OPERATION (see Figure 1) TWO-CELL OPERATION (see Figure 2) No load 125 µA 125 µA RL = 120 Ω 525 mA 405 mA No ac input 7.2 V 8.6 V With ac input 8.6 V 10 V 40 mA 80 mA PARAMETER Input current Output voltage Output current capability Efficiency Battery life (AA NiCad) no load 66% 66% 60 days 166 days POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 4–5 TL496C, TL496Y 9-VOLT POWER-SUPPLY CONTROLLERS SLVS012B – AUGUST 1978 – REVISED AUGUST 1995 functional description The TL496C is designed to operate from either a single-cell or two-cell battery source. To operate the device from a single cell (1.1 V to 1.5 V), the source must be connected to both inputs 1C INPUT and 2C INPUT as shown in Figure 1. For a two-cell operation (2.3 V to 3 V), the input is applied to 2C INPUT only and 1C INPUT is left open (see Figure 2). battery operation The TL496C operates as a switching regulator from a battery input. The cycle is initiated when a low-voltage condition is sensed by the internal feedback (the thresholds at terminals 1 and 8 are approximately 7.2 and 8.6 V respectively). An internal latch is set and the output transistor is turned on. This causes the current in the external inductor (L) to increase linearly until it reaches a peak value of approximately 1 A. When the peak current is sensed, the internal latch is reset and the output transistor is turned off. The energy developed in the inductor is then delivered to the output storage capacitor through the blocking diode. The latch remains in the off state until the feedback signal indicates the output voltage is again deficient. transformer-coupled operation The TL496C operates on alternate half cycles of the ac input during transformer-coupled operation to first sustain the output voltage and second to recharge the batteries. The TL496C performs like a series regulator to supply charge to the output filter/storage capacitor during the first half cycle. The output voltage of the series regulator is slightly higher than that created by the switching circuit. This maintains the feedback voltage above the switching regulator control circuit threshold, effectively inhibiting the switching control circuitry. During the second half cycle, an external diode (1N4001) is used to clamp the negative-going end of the transformer secondary to ground, thus allowing the positive-going end (end connected to V+ side of battery) to pump a charge into the standby batteries. 4–6 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL APPLICATIONS”). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER’S RISK. In order to minimize risks associated with the customer’s applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of TI covering or relating to any combination, machine, or process in which such semiconductor products or services might be or are used. TI’s publication of information regarding any third party’s products or services does not constitute TI’s approval, warranty or endorsement thereof. Copyright 1998, Texas Instruments Incorporated