KA7500B - SMPS PWM Controller DIP-16 | onsemi
MPN: KA7500B ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.12 | $1.12 |
| 10 | $0.98 | $9.80 |
| 100 | $0.82 | $82.00 |
| 500 | $0.71 | $355.00 |
| 1,000 | $0.63 | $630.00 |
| 3,000 | $0.54 | $1,620.00 |
KA7500B Overview
A PWM controller (Pulse-Width Modulation controller) is a key building block in the power management IC hierarchy: PWM controller -> SMPS controller -> DC-DC controller -> power management IC. It regulates an output voltage by varying the duty cycle of a switching element (MOSFET or BJT) at a fixed frequency, enabling high-efficiency power conversion versus linear regulation. The KA7500B is a voltage-mode controller, meaning it regulates by comparing an error-amplifier output against an internal sawtooth ramp - a topology prized for its simplicity, predictable loop compensation, and noise immunity.
Key features include a stable on-chip 5 V reference trimmed to 5%, uncommitted output transistors rated for 200 mA sink or source current, variable dead-time control on pin 4 for cross-conduction prevention, output mode selection for either push-pull (half-bridge/full-bridge) or single-ended operation, and a complete PWM power-control circuitry including error amplifiers, oscillator, and reference. The on-chip oscillator can be synchronized to an external master clock for multi-rail power systems, and the uncommitted outputs enable flexible topology choice. Operating temperature range is typically 0C to 70C (commercial grade).
Typical applications include ATX/PC power supplies, DC-DC buck/boost/half-bridge converters, solar inverters, and uninterruptible power supplies. It also appears in welding equipment, induction heaters, and motor drives where TL494-class TL494 replacements are needed. The Ka7500B's DIP-16 through-hole package simplifies prototyping, repair, and retrofit work on legacy PCBs that were designed around the TL494 pinout.
When designing with this device, ensure the oscillator timing resistor RT and capacitor CT are selected to set the switching frequency below 300 kHz with adequate margin. Add proper bypass capacitance on VCC and VREF, and use the dead-time control pin to set the minimum off-time to prevent simultaneous conduction of the push-pull output transistors.
This page synthesizes distributor pricing, drop-in TL494-family alternatives, and practical design notes not consolidated in any single manufacturer datasheet.
Drop-in alternatives for KA7500B — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
TL494CN
✅ Drop-In📋 Reference alternative (not in catalog)
TL494IN
✅ Drop-In📋 Reference alternative (not in catalog)
SG2525AN
✅ Drop-In📋 Reference alternative (not in catalog)
KA7500B Maximum Ratings & Electrical Characteristics
| Function | SMPS controller, voltage-mode PWM |
| Topology Support | Buck, push-pull, single-ended |
| Package | 16-PDIP (DIP-16, through-hole) |
| Pin Count | 16 |
| Supply Voltage (Vcc) | Up to 42 V (max) |
| Switching Frequency | Up to 300 kHz (programmable via RT/CT) |
| Maximum Duty Cycle | 45% (per datasheet) |
| Internal Reference Voltage | 5 V, trimmed to 5% |
| Output Drive Current | 200 mA sink or source |
| Output Configuration | Push-pull or single-ended (selectable) |
| Dead-Time Control | Variable via pin 4 |
| Oscillator | On-chip, master/slave sync capable |
| Operating Temperature | 0C to 70C (typical, commercial grade) |
| Mounting Type | Through-hole |
KA7500B Pin Configuration
| Pin 1 | 1IN+ — Error amplifier 1 non-inverting input |
| Pin 2 | 1IN- — Error amplifier 1 inverting input |
| Pin 3 | FB — Feedback / error amplifier 1 output |
| Pin 4 | DTC — Dead-time control |
| Pin 5 | CT — Oscillator timing capacitor |
| Pin 6 | RT — Oscillator timing resistor |
| Pin 7 | GND — Ground |
| Pin 8 | C1 — Output 1 collector |
| Pin 9 | E1 — Output 1 emitter |
| Pin 10 | E2 — Output 2 emitter |
| Pin 11 | C2 — Output 2 collector |
| Pin 12 | VCC — Positive supply voltage |
| Pin 13 | OC — Output control (push-pull vs single-ended) |
| Pin 14 | VREF — 5V internal reference output |
| Pin 15 | 2IN- — Error amplifier 2 inverting input |
| Pin 16 | 2IN+ — Error amplifier 2 non-inverting input |
Typical Applications
KA7500B is suitable for 6 applications: ATX PC Power Supply, DC-DC Buck Converter, Solar Inverter / Off-Grid Power, Welding Equipment / Induction Heater, Uninterruptible Power Supply (UPS), Motor Drive / DC Motor Speed Control.
ATX PC Power Supply
The KA7500B is the primary PWM controller in legacy ATX/PC SMPS designs, replacing the original TL494 controller. Its 5V trimmed reference, 200mA push-pull output drive, and 300 kHz switching capability match the ATX power supply topology requirements, including push-pull half-bridge and full-bridge configurations. Place the KA7500B on the primary side with VCC supplied by an auxiliary 12-18V rail, and drive the main switching MOSFETs directly from the 200mA output transistors. Compared to the TL494, KA7500B offers equivalent electrical performance at lower quiescent current and improved thermal stability, making it well-suited for continuous-load ATX supplies that previously relied on aging TL494 inventory.
Recommended
DC-DC Buck Converter
The KA7500B implements voltage-mode control in step-down (buck) DC-DC converters, where its 5V reference sets the output voltage and the internal error amplifier compares the feedback against the sawtooth ramp. Single-ended output mode drives a single high-side MOSFET through a gate driver or directly at low currents; the dead-time control on pin 4 prevents cross-conduction when paired with synchronous rectification. The 300 kHz maximum frequency enables compact inductor sizing, and the 42 V VCC rating supports 24 V and 36 V input bus designs common in industrial and telecom applications.
Recommended
Solar Inverter / Off-Grid Power
In off-grid solar inverters, the KA7500B drives a push-pull or full-bridge inverter stage that converts DC battery/solar input to AC mains or AC auxiliary output. Its voltage-mode control is well-suited to inverter topologies where predictable loop compensation matters, and the 200 mA drive capability handles small to medium MOSFET gates directly. The on-chip oscillator can be synchronized to an external master for grid-tie phase-lock applications, and the dead-time control prevents shoot-through in the bridge. KA7500B is preferred in retrofit solar inverter repairs due to its DIP-16 through-hole package and TL2315.
Recommended
Welding Equipment / Induction Heater
The KA7500B drives the resonant tank in induction heating and welding equipment, where the high peak currents require robust push-pull drive. Its 42 V VCC rating supports battery-powered or rectified mains inputs up to 30 V, and the variable dead-time control optimizes ZVS (zero-voltage switching) timing for the resonant tank. The 200 mA output drive is sufficient for small to medium IGBT or MOSFET gates typically used in portable induction heaters. The DIP-16 through-hole package is preferred for repairability of legacy induction heater units originally designed around TL2315.
Recommended
Uninterruptible Power Supply (UPS)
In line-interactive and online UPS systems, the KA7500B controls the battery charger and inverter stages. Its voltage-mode control regulates the battery charge voltage by varying PWM duty cycle into the charger buck converter, and the same IC drives the inverter bridge during mains failure. The 5V trimmed reference provides a stable feedback reference for the charge controller, and the 300 kHz switching frequency keeps the magnetics small. DIP-16 through-hole packaging suits the high-reliability repair market for legacy UPS units.
Recommended
Motor Drive / DC Motor Speed Control
The KA7500B drives H-bridge motor drives for DC motor speed control, where variable duty cycle PWM directly regulates motor speed and torque. Single-ended output mode can drive a low-side switch, or push-pull mode drives an H-bridge with dead-time control preventing shoot-through. The 5V reference provides a stable speed setpoint reference, and the internal error amplifier closes the speed regulation loop from a tachogenerator or back-EMF feedback. The DIP-16 through-hole package suits hobby and small-industrial motor controllers, especially retrofit repairs of vintage motor drives.
Recommended
Recommended Products Summary
Engineering reference data for KA7500B — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | TL494CN | TL494IN | TL494CD | SG2525AN |
|---|---|---|---|---|---|
| Package | 16-PDIP (DIP-16) | 16-PDIP (DIP-16) - same | 16-PDIP (DIP-16) - same | SOIC-16 - different footprint | 16-PDIP (DIP-16) - same |
| Brand | onsemi | Texas Instruments | Texas Instruments | Texas Instruments | Microchip Technology |
| Function | Voltage-mode PWM controller | Voltage-mode PWM controller | Voltage-mode PWM controller | Voltage-mode PWM controller | Current-mode PWM controller |
| Supply Voltage (max) | 42 V | 42 V | 42 V | 42 V | 40 V |
| Max Switching Frequency | 300 kHz | 300 kHz | 300 kHz | 300 kHz | 400 kHz |
| Output Drive Current | 200 mA | 200 mA | 200 mA | 200 mA | 500 mA |
| Internal Reference | 5V / 5% | 5V / 5% | 5V / 5% | 5V / 5% | 5V / 1% |
| Operating Temperature | 0C to 70C | 0C to 70C | -40C to 85C | 0C to 70C | 0C to 70C |
Key Differentiators
- Pin-for-pin functional equivalent to TL494 with same DIP-16 footprint (vs TL494CN (Texas Instruments))
- Through-hole DIP-16 package simplifies prototyping and legacy repair (vs TL494CD (TI SOIC-16))
- Voltage-mode control topology for predictable loop compensation (vs SG2525AN (Microchip current-mode))
Design Notes
Place RT and CT oscillator components as close as possible to pins 5 and 6 to minimize noise pickup that can shift the oscillator frequency. Keep the oscillator ground return separate from the high-current output ground and join them only at the KA7500B GND pin (pin 7). Use a 0.1uF ceramic decoupling capacitor on VCC (pin 12) placed within 5mm of the pin, and a 1uF to 10uF bulk capacitor on VREF (pin 14) to stabilize the 5V reference against output switching transients.
Estimated: At 300kHz switching and 200mA peak output drive with VCC=15V, the KA7500B internal dissipation is approximately 100mW (VCC quiescent plus output drive losses). DIP-16 has theta_JA of approximately 80C/W, yielding a junction temperature rise of 8C above ambient at room temperature. At maximum VCC=42V the quiescent dissipation rises to ~300mW, requiring verification in worst-case thermal testing. No heatsink is required in typical applications, but provide adequate copper pour on GND pin 7 for heat spreading.
Do not exceed the absolute maximum VCC of 42V - use a clamp or pre-regulator if the input bus can exceed 42V during transients. The dead-time control pin (4) must be connected to a defined voltage; leaving it floating causes undefined duty cycle behavior. For push-pull mode, verify the dead-time array with both outputs OFF to prevent shoot-through in the driven half-bridge. The OC pin (13) selects push-pull (high) or single-ended (low) output mode and must be tied to a logic level, not left floating.
Compliance Information
RoHS / REACH / lead-free status not explicitly listed in the verified web data. onsemi product page should be consulted for the latest compliance documentation. AEC-Q100 not applicable as KA7500B is a commercial-grade PWM controller.
