TL497ACDR


    
  
  
 
 
 
 SLVS009F − JUNE 1976 − REVISED FEBRUARY 2005 D D D D D D D D D D, N, OR PW PACKAGE (TOP VIEW) High Efficiency . . . 60% or Greater Peak Switch Current . . . 500 mA Input Current Limit Protection TTL-Compatible Inhibit Adjustable Output Voltage Input Regulation . . . 0.2% Typ Output Regulation . . . 0.4% Typ Soft Start-Up Capability Can be Used in Buck, Boost, and Inverting Configurations COMP INPUT INHIBIT FREQ CONTROL SUBSTRATE GND CATHODE ANODE 1 14 2 13 3 12 4 11 5 10 6 9 7 8 VCC CUR LIM SENS BASE DRIVE† BASE† COL OUT NC EMIT OUT NC − No internal connection † BASE (11) and BASE DRIVE (12) are used for device testing only. They normally are not used in circuit applications of the device. description/ordering information The TL497A incorporates all the active functions required in the construction of switching voltage regulators. It also can be used as the control element to drive external components for high-power-output applications. The TL497A was designed for ease of use in step-up, step-down, or voltage-inversion applications requiring high efficiency. The TL497A is a fixed-on-time variable-frequency switching-voltage-regulator control circuit. The switch-on time is programmed by a single external capacitor connected between FREQ CONTROL and GND. This capacitor, CT, is charged by an internal constant-current generator to a predetermined threshold. The charging current and the threshold vary proportionally with VCC. Thus, the switch-on time remains constant over the specified range of input voltage (4.5 V to 12 V). Typical on times for various values of CT are as follows: TIMING CAPACITOR, CT (pF) ON TIME (µs) 200 250 350 400 500 750 1000 1500 2000 19 22 26 32 44 56 80 120 180 The output voltage is controlled by an external resistor ladder network (R1 and R2 in Figures 1, 2, and 3) that provides a feedback voltage to the comparator input. This feedback voltage is compared to the reference voltage of 1.2 V (relative to SUBSTRATE) by the high-gain comparator. When the output voltage decays below the value required to maintain 1.2 V at the comparator input, the comparator enables the oscillator circuit, which charges and discharges CT as described above. The internal pass transistor is driven on during the charging of CT. The internal transistor can be used directly for switching currents up to 500 mA. Its collector and emitter are uncommitted, and it is current driven to allow operation from the positive supply voltage or ground. An internal Schottky diode matched to the current characteristics of the internal transistor also is available for blocking or commutating purposes. The TL497A also has on-chip current-limit circuitry that senses the peak currents in the switching regulator and protects the inductor against saturation and the pass transistor against overstress. The current limit is adjustable and is programmed by a single sense resistor, RCL, connected between VCC and CUR LIM SENS. The current-limit circuitry is activated when 0.7 V is developed across RCL. External gating is provided by the INHIBIT input. When the INHIBIT input is high, the output is turned off. Simplicity of design is a primary feature of the TL497A. With only six external components (three resistors, two capacitors, and one inductor), the TL497A operates in numerous voltage-conversion applications (step-up, step-down, invert) with as much as 85% of the source power delivered to the load. The TL497A replaces the TL497 in all applications. The TL497AC is characterized for operation from 0°C to 70°C. The TL497AI is characterized for operation from −40°C to 85°C. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. Copyright  2005, Texas Instruments Incorporated 
 
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 SLVS009F − JUNE 1976 − REVISED FEBRUARY 2005 AVAILABLE OPTIONS PACKAGED DEVICES CHIP FORM (Y) TA SMALL-OUTLINE (D) PLASTIC DIP (N) SHRINK SMALL-OUTLINE (PW) 0°C to 70°C TL497ACD TL497ACN TL497ACPW TL497AY −40°C to 85°C TL497AID TL497AIN — — The D and PW packages are only taped and reeled. Add the suffix R to the device type (e.g., TL497ACPWR). Chip forms are tested at 25°C. functional block diagram BASE† BASE DRIVE† CUR LIM SENS FREQ CONTROL INHIBIT COMP INPUT SUBSTRATE CATHODE 11 12 13 Current Limit Sense 3 2 Oscillator 1 4 10 1.2-V Reference 8 6 7 † BASE and BASE DRIVE are used for device testing only. They normally are not used in circuit applications of the device. 2 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 COL OUT EMIT OUT ANODE  
    
  
  
 
 
 
 SLVS009F − JUNE 1976 − REVISED FEBRUARY 2005 absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† Supply voltage, VCC (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 V Output voltage, VO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 V Input voltage, VI(COMP INPUT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 V Input voltage, VI(INHIBIT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 V Diode reverse voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 V Power switch current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750 mA Diode forward current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750 mA Package thermal impedance, θJA (see Notes 2 and 3): D package . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86°C/W N package . . . . . . . . . . . . . . . . . . . . . . . . . . . 101°C/W PW package . . . . . . . . . . . . . . . . . . . . . . . . . . 113°C/W Lead temperature 1,6 mm (1/16 inch) from case for 60 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65°C to 150°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. NOTES: 1. All voltage values, except diode voltages, are with respect to network ground terminal. 2. Maximum power dissipation is a function of TJ(max), θJA, and TA. The maximum allowable power dissipation at any allowable ambient temperature is PD = (TJ(max) − TA)/θJA. Operating at the absolute maximum TJ of 150°C can impact reliability. 3. The package thermal impedance is calculated in accordance with JESD 51, except for through-hole packages, which use a trace length of zero. recommended operating conditions Supply voltage, VCC High-level input voltage, VIH INHIBIT pin Low-level input voltage, VIL INHIBIT pin MAX 4.5 12 2.5 Step-down configuration (see Figure 2) VI + 2 Vref Inverting regulator (see Figure 3) −Vref UNIT V V 0.8 Step-up configuration (see Figure 1) Output voltage MIN V 30 VI − 1 −25 V Power switch current 500 mA Diode forward current 500 mA TL497AC Operating free-air temperature range, TA TL497AI POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 0 70 −40 85 °C 3 
    
  
  
 
 
 
  SLVS009F − JUNE 1976 − REVISED FEBRUARY 2005 electrical characteristics over recommended operating conditions, VCC = 6 V (unless otherwise noted) PARAMETER TA† TEST CONDITIONS High-level input current, INHIBIT Low-level input current, INHIBIT Comparator reference voltage Comparator input bias current MIN TL497AC TYP‡ MAX UNIT Full range 0.8 1.5 0.8 1.5 mA Full range 5 10 5 20 µA VI = 4.5 V to 6 V VI = 6 V Full range 1.2 1.32 1.2 1.26 V 40 100 40 100 µA 0.13 0.2 0.13 0.2 Switch on-state voltage VI = 4.5 V Switch off-state current VI = 4.5 V, VO = 30 V Sense voltage, CUR LIM SENS VI = 6 V IO = 10 mA 1.08 Full range 25°C Full range Full range 10 25°C 1.14 0.85 25°C Diode reverse voltage TL497AI TYP‡ MAX VI(I) = 5 V VI(I) = 0 V IO = 100 mA IO = 500 mA Diode forward voltage MIN 1 50 10 200 0.45 1 50 500 0.45 1 Full range 0.75 0.85 0.75 0.95 IO = 100 mA IO = 500 mA Full range 0.9 1 0.9 1.1 Full range 1.33 1.55 1.33 1.75 IO = 500 µA IO = 200 µA Full range Full range V V V 11 Full range 25°C Off-state supply current µA A 30 30 25°C On-state supply current V 14 11 15 6 Full range 14 16 9 6 10 mA 9 11 mA † Full range is 0°C to 70°C for the TL497AC and −40°C to 85°C for the TL497AI. ‡ All typical values are at TA = 25°C. electrical characteristics over recommended operating conditions, VCC = 6 V, TA = 25°C (unless otherwise noted) TL497AY PARAMETER TEST CONDITIONS High-level input current, INHIBIT Low-level input current, INHIBIT Comparator reference voltage Comparator input bias current Switch on-state voltage 4 MIN TYP MAX UNIT VI(I) = 5 V VI(I) = 0 V 0.8 mA 5 µA VI = 4.5 V to 6 V VI = 6 V 1.2 V 40 µA Switch off-state current VI = 4.5 V, VI = 4.5 V, IO = 100 mA VO = 30 V 0.13 V 10 µA IO = 10 mA IO = 100 mA 0.75 Diode forward voltage IO = 500 mA 1.33 0.9 V On-state supply current 11 mA Off-state supply current 6 mA POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 
    
  
  
 
 
 
  SLVS009F − JUNE 1976 − REVISED FEBRUARY 2005 APPLICATION INFORMATION L RCL VO VI 14 13 10 8 DESIGN EQUATIONS R1 TL497A I (PK) + 2 I max O 2 3 4 5 6 7 C (pF) [ 12 t on (ms) T RCL L R1 + (V VI VO R 13 10 3 4 CO 5 CL O – 1.2 V) kW + 0.5 V I (PK) R1 8 TL497A 2 I t (ms) on (PK) Choose L (50 to 500 µH), calculate ton (25 to 150 µs) BASIC CONFIGURATION (Peak Switching Current = I(PK) < 500 mA) 1 O V I V I R2 = 1.2 kΩ CT 14 V CO L (mH) + 1 ƪ ƫ C O (mF) [ t on(ms) ƪ V V I I ) I (PK) O O V ripple ƫ (PK) R2 = 1.2 kΩ CT EXTENDED POWER CONFIGURATION (using external transistor) Figure 1. Positive Regulator, Step-Up Configurations POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5 
    
  
  
 
 
 
  SLVS009F − JUNE 1976 − REVISED FEBRUARY 2005 APPLICATION INFORMATION RCL L VO VI 14 13 10 DESIGN EQUATIONS 8 R1 TL497A 1 3 2 I CO 4 5 6 7 (PK) + 2I L (mH) + O max V –V I O t on(ms) I (PK) R2 = 1.2 kΩ Choose L (50 to 500 µH), calculate ton (10 to 150 µs) CT C (pF) [ 12 t on(ms) T BASIC CONFIGURATION (Peak Switching Current = I(PK) < 500 mA) RCL R1 + (V L VO VI R C 14 13 10 8 2 3 4 O + (mF) [ t on(ms) CO 5 6 7 R2 = 1.2 kΩ CT EXTENDED POWER CONFIGURATION (using external transistor) Figure 2. Positive Regulator, Step-Down Configurations 6 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 – 1.2 V) kW 0.5 V I (PK) R1 TL497A 1 CL O ƪ V I *V V O O V I (PK) ripple ) I (PK) O ƫ 
    
  
  
 
 
 
 SLVS009F − JUNE 1976 − REVISED FEBRUARY 2005 APPLICATION INFORMATION L RCL VI DESIGN EQUATIONS 14 13 10 8 R1 † I 2 3 ƫ Ť Ť CO TL497A 1 ƪ V + 2 I max 1 ) O (PK) O V I 4 L (mH) + R2 = 1.2 kΩ 5 VO CT V I I t (ms) on (PK) Choose L (50 to 500 µH), calculate ton (10 to 150 µs) C (pF) [ 12 t on(ms) T BASIC CONFIGURATION (Peak Switching Current = I(PK) < 500 mA) RCL R1 + L R VI C 14 13 10 8 R1 2 3 4 O + 0.5 V I (PK) (mF) [ t on(ms) ƪŤ V V I O Ť I(PK) ) IO V ripple ƫ (PK) † TL497A 1 CL ǒŤ VOŤ – 1.2 VǓ kW CO 5 R2 = 1.2 kΩ VO CT EXTENDED POWER CONFIGURATION (using external transistor) † Use external catch diode, e.g., 1N4001, when building an inverting supply with the TL497A. Figure 3. Inverting Applications POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 7 
    
  
  
 
 
 
  SLVS009F − JUNE 1976 − REVISED FEBRUARY 2005 APPLICATION INFORMATION Switching Circuit VI VO 3-Term Reg < 12 V Control 14 13 TL497A 5 EXTENDED INPUT CONFIGURATION WITHOUT CURRENT LIMIT RCL VI Switching Circuit VO DESIGN EQUATIONS Q1 Vreg 3-Term Reg < 12 V V 10 mA R CL + 1 kΩ R1 ) Control R2 14 5 Q2 CURRENT LIMIT FOR EXTENDED INPUT CONFIGURATION Figure 4. Extended Input Voltage Range (VI > 12 V) 8 I B(Q2) Ǔ R2 + V reg * 1 10 kW TL497A R1 BE(Q1) limit (PK) V I ǒ 13 I POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 PACKAGE OPTION ADDENDUM www.ti.com 14-Aug-2021 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) TL497ACD ACTIVE SOIC D 14 50 RoHS & Green NIPDAU Level-1-260C-UNLIM 0 to 70 TL497AC TL497ACDR ACTIVE SOIC D 14 2500 RoHS & Green NIPDAU Level-1-260C-UNLIM 0 to 70 TL497AC TL497ACN ACTIVE PDIP N 14 25 RoHS & Green NIPDAU N / A for Pkg Type 0 to 70 TL497ACN TL497ACNE4 ACTIVE PDIP N 14 25 RoHS & Green NIPDAU N / A for Pkg Type 0 to 70 TL497ACN TL497ACNSR ACTIVE SO NS 14 2000 RoHS & Green NIPDAU Level-1-260C-UNLIM 0 to 70 TL497A TL497ACPWR ACTIVE TSSOP PW 14 2000 RoHS & Green NIPDAU Level-1-260C-UNLIM 0 to 70 T497A TL497AID ACTIVE SOIC D 14 50 RoHS & Green NIPDAU Level-1-260C-UNLIM -40 to 85 TL497AI TL497AIDR ACTIVE SOIC D 14 2500 RoHS & Green NIPDAU Level-1-260C-UNLIM -40 to 85 TL497AI TL497AIN ACTIVE PDIP N 14 25 RoHS & Green NIPDAU N / A for Pkg Type -40 to 85 TL497AIN (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of