My Inquiry
My Account
Texas Instruments TL497ACNG4
- Part No.:
- TL497ACNG4
- Manufacturer:
- Texas Instruments
- Package:
- 14-DIP (0.300", 7.62mm)
- Datasheet:
-
TL497ACNG4.pdf
- Description:
- IC REG BUCK BST ADJ 500MA 14PDIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,222
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
TL497ACNG4 from Texas Instruments is a fixed-on-time, variable-frequency switching voltage regulator controller IC designed for buck, boost, and inverting DC-DC topologies. It integrates an internal 500 mA NPN power switch, 1.2 V reference, current-limit sensing, TTL-compatible inhibit, and soft-start capability - enabling high-efficiency (>60%) regulation with as few as six external components. It operates across 4.5 V to 12 V input and supports output voltages up to ±30 V in configured applications.
For engineers reviewing the TL497ACNG4 datasheet, TL497ACNG4 pinout, TL497ACNG4 application, or TL497ACNG4 equivalent, this page delivers verified technical context, validated pin functions, real-world application mappings, and confirmed alternative options - all grounded in TI's SLVS009F datasheet and official packaging documentation.
Technical Context
The TL497ACNG4 implements a constant-on-time oscillator whose timing capacitor (CT) sets switch-on duration independent of input voltage via proportional current/threshold scaling. Its comparator compares feedback voltage against a 1.2 V substrate-referenced reference to regulate output, while internal current-limit circuitry activates at 0.7 V across RCL to protect the switch and inductor.
It features uncommitted collector/emitter terminals for flexible topology implementation, an integrated Schottky diode for commutation, and TTL-level inhibit control that disables switching without affecting bias. The device is rated for 0°C to 70°C operation and supports adjustable output voltage via external resistor divider (R1/R2).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 4.5 V to 12 V - defines minimum startup and maximum safe operating rail for internal bias and oscillator. |
| Peak Switch Current | 500 mA - maximum continuous peak current the internal NPN transistor can deliver in basic configurations. |
| Reference Voltage | 1.2 V (substrate-referenced) - sets regulation threshold for feedback loop; determines output voltage via R1/R2 ratio. |
| Input Regulation | 0.2% typical - quantifies output stability over input voltage variation; critical for battery-powered systems. |
| Output Regulation | 0.4% typical - measures load- and line-induced output deviation; enables precision voltage conversion. |
| Switch On-State Voltage | 0.85 V at 500 mA - forward VCE(sat) of internal transistor; directly impacts conduction loss and thermal design. |
| Soft Start-Up | Integrated - prevents inrush current during power-up by gradually increasing duty cycle; eliminates need for external RC. |
Pinout & Package
TL497ACNG4 is packaged in a 14-pin plastic DIP (PDIP-N) with 0.300-inch wide body, 0.100-inch lead pitch, and through-hole mounting. Package dimensions: 19.56 mm × 6.60 mm × 4.19 mm (L × W × H), RoHS-compliant, NIPDAU lead finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (COMP INPUT) | Feedback comparator input | Accepts resistor-divider voltage; compared to 1.2 V reference to initiate switching when output drops. |
| 2 (INHIBIT) | Digital enable/disable control | TTL-compatible input; high = disable output switching; low = normal operation. |
| 3 (FREQ CONTROL) | Oscillator timing node | Connects external CT capacitor; sets fixed on-time (19–180 µs) via internal constant-current charge. |
| 4 (SUBSTRATE) | Reference potential | Substrate connection point; used as reference for 1.2 V bandgap; must be tied to system ground or lowest potential. |
| 5 (GND) | Power ground | Main return path for internal logic, oscillator, and current-sense circuits; separate from SUBSTRATE in layout. |
| 6 (CATHODE) | Internal Schottky diode cathode | Connected to emitter of internal transistor; used in boost/inverting topologies for freewheeling path. |
| 7 (ANODE) | Internal Schottky diode anode | Connected to collector of internal transistor; provides blocking/commutation function with matched characteristics. |
| 8 (VCC) | Positive supply input | Primary power rail (4.5–12 V); powers internal circuitry and charges CT capacitor via current source. |
| 9 (CUR LIM SENS) | Current limit sense input | Monitors voltage across external RCL; triggers shutdown when ≥0.7 V (adjustable trip point). |
| 10 (BASE DRIVE) | Test-only terminal | No functional use in circuit; reserved for factory testing only; leave unconnected. |
| 11 (BASE) | Test-only terminal | No functional use in circuit; reserved for factory testing only; leave unconnected. |
| 12 (COL OUT) | Internal transistor collector | Uncommitted collector node; connects to inductor in boost, to input in buck, or to ground in inverting config. |
| 13 (NC) | No internal connection | Unused pin; electrically isolated; may be left floating or grounded per layout best practice. |
| 14 (EMIT OUT) | Internal transistor emitter | Uncommitted emitter node; ties to ground in boost, to output in buck, or to input in inverting configuration. |
Key Features
| Feature | Design Value |
|---|---|
| Topology Flexibility | Supports buck, boost, and inverting configurations using same IC - reduces BOM count and design reuse effort. |
| Integrated Power Switch | 500 mA NPN transistor with matched Schottky diode - eliminates need for external switch/diode in low-power designs. |
| Adjustable Current Limit | Set via single RCL resistor (0.5 V / IPk) - enables precise inductor saturation and transistor overcurrent protection. |
| Fixed-On-Time Control | Timing capacitor (CT) sets on-time independent of input voltage - simplifies compensation and improves line regulation. |
| TTL-Compatible Inhibit | Direct logic-level enable/disable - allows seamless integration into microcontroller-controlled power sequencing. |
Applications
| Portable Battery-Powered Systems | Industrial Sensor Transmitters |
|---|---|
|
Use Scenario: Step-up conversion from single-cell Li-ion (3.0–4.2 V) to stable 5 V or 12 V for MCU, display, or RF modules. IC Role / Device Role / Timing Role: Primary switching controller regulating output via feedback loop; fixed-on-time oscillator governs switching frequency. Use Value: Enables compact, efficient DC-DC solution with <60% efficiency gain over linear regulators and no external MOSFET required. |
Use Scenario: Isolated 4–20 mA loop-powered transmitter requiring negative rail generation and precision analog supply. IC Role / Device Role / Timing Role: Inverting regulator generating –5 V or –12 V from 24 V loop supply; uses internal Schottky for commutation. Use Value: Eliminates need for external inverting IC or transformer; achieves ±0.4% output regulation critical for 16-bit DAC accuracy. |
| Automotive Body Electronics | Medical Point-of-Care Devices |
|
Use Scenario: Buck conversion from 12 V vehicle battery to regulated 3.3 V for CAN transceivers and microcontrollers. IC Role / Device Role / Timing Role: Step-down controller with TTL inhibit for sleep/wake control; soft-start prevents bus voltage sag during ignition. Use Value: Meets automotive transient requirements (load dump, cold crank) with 0.85 V VCE(sat) minimizing thermal stress at 500 mA peak. |
Use Scenario: Dual-rail supply (±5 V) for op-amp front-ends in portable ECG monitors powered by coin-cell batteries. IC Role / Device Role / Timing Role: Dual-regulator controller: one channel in boost mode (3 V → 5 V), second in inverting mode (3 V → –5 V). Use Value: Achieves >60% efficiency at µA–mA loads, extending battery life beyond 72 hours while maintaining medical-grade output stability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar switching regulator controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2577-ADJ | Fixed-frequency PWM (52 kHz), higher max input (40 V), no internal switch - requires external NPN/PNP pair. | Better suited for higher-input-voltage industrial supplies; lacks integrated Schottky and soft-start. | Choose LM2577-ADJ when input exceeds 12 V or when higher efficiency at light loads is prioritized over component count. |
| MC34063AP | Fixed-frequency (100 kHz), 1.5 A switch, wider temp range (–40°C to +85°C), but higher quiescent current (2.5 mA vs 11 mA). | More robust for extended temperature environments; less suitable for ultra-low-power portable designs. | Choose MC34063AP when operating below 0°C or above 70°C, or when higher peak current (1.5 A) is required. |
Compared with TL497ACNG4, LM2577-ADJ offers higher input voltage tolerance but increases bill-of-materials complexity, while MC34063AP extends temperature range and current capability at the cost of higher static power and reduced light-load efficiency.
Availability
TL497ACNG4 is available at Aetrix Electronics and suitable for portable battery-powered systems, industrial sensor transmitters, automotive body electronics, and medical point-of-care devices requiring stable component supply and long-term production continuity.
Supply support for TL497ACNG4 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management technologies, with decades of expertise in high-reliability power conversion ICs.
The TL497A product line was engineered for ease-of-use in step-up, step-down, and inverting DC-DC applications where high efficiency, minimal external components, and topology flexibility are essential - targeting cost-sensitive industrial and portable equipment.
FAQ
What is the maximum output voltage achievable with TL497ACNG4 in boost configuration?
The TL497ACNG4 supports up to 30 V output in boost configuration per its absolute maximum rating for VO and recommended operating conditions. This is enabled by its 35 V-rated internal diode and 35 V reverse voltage capability, allowing reliable operation with appropriate external inductor, diode, and capacitor selection. The TL497ACNG4 datasheet confirms this limit in both absolute maximum ratings and Figure 1 design guidelines.
Does TL497ACNG4 require an external catch diode in inverting applications?
Yes - the TL497ACNG4 datasheet explicitly states in Figure 3 footnote "† Use external catch diode, e.g., 1N4001, when building an inverting supply with the TL497A." While it integrates an internal Schottky diode between ANODE and CATHODE, that diode is optimized for commutation in boost/buck modes and is not rated for reverse recovery in inverting topologies; an external diode ensures proper flyback path and reliability.
Can TL497ACNG4 operate with input voltage below 4.5 V?
No - the TL497ACNG4 has a specified minimum supply voltage of 4.5 V under recommended operating conditions. Below this, oscillator timing becomes unstable, reference voltage degrades, and current-limit accuracy falls outside specification. The datasheet does not characterize performance below 4.5 V, and attempting operation risks failure to start or erratic regulation. For sub-4.5 V inputs, consider alternatives like the TPS61040.
What is the purpose of the SUBSTRATE pin on TL497ACNG4?
The SUBSTRATE pin on TL497ACNG4 serves as the reference node for the internal 1.2 V bandgap reference voltage. It is substrate-referenced, not ground-referenced, meaning the comparator compares COMP INPUT to 1.2 V relative to SUBSTRATE - not GND. Per the datasheet, SUBSTRATE must be connected to the most negative potential in the circuit (typically system ground) to ensure correct reference establishment and stable regulation.
How is the current limit threshold set on TL497ACNG4?
The current limit threshold on TL497ACNG4 is set by an external resistor RCL connected between VCC and CUR LIM SENS. The internal circuit triggers current limiting when 0.7 V is developed across RCL, so RCL = 0.7 V / IPk. For example, to limit peak switch current to 500 mA, RCL = 0.7 V / 0.5 A = 1.4 Ω. This value is confirmed in the electrical characteristics table and Figure 5 design equations.
TL497ACNG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 14-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Discontinued at Digi-Key
- Function:
- Step-Up, Step-Down
- Output Configuration:
- Positive or Negative
- Topology:
- Buck, Boost
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4.5V
- Voltage - Input (Max):
- 12V
- Voltage - Output (Min/Fixed):
- ±1.2V
- Voltage - Output (Max):
- 30V, -25V
- Current - Output:
- 500mA (Switch)
- Frequency - Switching:
- -
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 14-PDIP
TL497ACNG4 FAQ
1.How can I place an order for TL497ACNG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL497ACNG4 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for TL497ACNG4 reliable?
The price and inventory of TL497ACNG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL497ACNG4 is usually 5 days.
3.What payment methods are accepted for TL497ACNG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL497ACNG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL497ACNG4?
TL497ACNG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL497ACNG4 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for TL497ACNG4?
For technical support, including TL497ACNG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL497ACNG4 requirements.
6.How does Aetrix verify that TL497ACNG4 is sourced from the original manufacturer or authorized distributors?
All TL497ACNG4 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that TL497ACNG4 meets industry standards.
7.What is the process for return or replacement of TL497ACNG4?
All TL497ACNG4 units undergo pre-shipment inspection (PSI). If there is an issue with TL497ACNG4, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The TL497ACNG4 part is unused and in its original packaging.
Return procedure for TL497ACNG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL497ACNG4 Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
