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Texas Instruments UCC2805D
- Part No.:
- UCC2805D
- Manufacturer:
- Texas Instruments
- Category:
- Power Supply Controllers, Monitors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
UCC2805D.pdf
- Description:
- IC REG CTRLR MULT TOPOLOGY 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:148
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Product details
Overview
UCC2805D from Texas Instruments is a low-power BiCMOS current-mode PWM controller for fixed-frequency DC-to-DC converters and battery-operated power supplies. It features 4 V reference voltage, 50% maximum duty cycle, 4.1 V turn-on threshold, 3.6 V turn-off threshold, and operates across –40°C to 125°C. Its internal leading-edge blanking and full-cycle soft start enable robust overcurrent protection in compact PSU designs.
For engineers reviewing the UCC2805D datasheet, UCC2805D pinout, UCC2805D application, or UCC2805D equivalent, key selection criteria include its 4 V reference, 50% duty limit, UVLO hysteresis of 0.5 V, 70 ns current-sense-to-output response, and SOIC-8 package compatibility with UC3842-family layouts.
Technical Context
The UCC2805D implements current-mode control using dual comparators on the CS pin - one for PWM regulation and one for overcurrent fault detection - with digital leading-edge blanking (50–150 ns) eliminating external RC filtering in most applications. Its error amplifier delivers 2 MHz bandwidth and true low-impedance output capable of sourcing/sinking current, enabling zero-duty-cycle forcing via COMP pin.
Oscillator frequency is set by an external RC network between REF and RC pins, with timing governed by f = 1.0/(R × C) for UCC2805D. The device uses BiCMOS process technology to achieve 100 μA start-up current and 500 μA typical operating supply current, supporting high-efficiency operation in space-constrained battery-powered systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 4.0 V ±2.5%, enabling precise feedback control in low-voltage battery-fed PSUs |
| UVLO Turn-On Threshold | 4.1 V ±0.4 V, ensuring reliable startup only after sufficient input rail stabilization |
| Max Duty Cycle | 50% ±2%, limiting conduction time for safe operation with synchronous rectifiers or transformer reset |
| CS to OUT Delay | 70 ns typical, minimizing propagation latency for fast current-loop response |
| Operating Temp Range | –40°C to +125°C, qualifying for automotive and industrial ambient environments |
| Start-Up Current | 100 μA typical, reducing auxiliary supply burden during initial power sequencing |
| Supply Current | 500 μA typical at no load, enabling ultra-low-quiescent operation in standby modes |
Pinout & Package
UCC2805D is housed in an 8-pin SOIC (D package), 3.91 mm × 4.90 mm body size, with Gull-wing leads and standard JEDEC MS-012AC footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - COMP | Error amplifier output / PWM comparator input | Low-impedance op-amp output that sources/sinks current; clamped during soft start to limit max duty cycle |
| 2 - FB | Inverting input of error amplifier | Receives feedback signal from output divider; requires short trace to minimize noise coupling and phase shift |
| 3 - CS | Current sense input to dual comparators | Connects directly to MOSFET source resistor; internal 100 ns leading-edge blanking prevents false triggering |
| 4 - RC | Oscillator timing node | RC network sets switching frequency per f = 1.0/(R × C); sensitive to layout - needs dedicated ground path |
| 5 - GND | Power and signal reference ground | Common return for all analog and power functions; must be low-inductance connection to minimize noise |
| 6 - OUT | Gate driver output | Totem-pole stage delivering ±750 mA peak; actively held low during UVLO for fail-safe MOSFET gate control |
| 7 - VCC | Supply input with UVLO monitoring | Powered via current-limiting resistor; internal Zener clamp at ~13.5 V protects against overvoltage |
| 8 - REF | 4 V reference output and logic supply | Bypassed with ≥0.1 µF ceramic; supplies internal logic and serves as RC timing bias source |
Key Features
| Feature | Design Value |
|---|---|
| Internal full-cycle soft start | Fixed 4 ms COMP ramp time eliminates need for external soft-start circuitry (1 R, 1 C, 1 PNP) |
| Digital leading-edge blanking | 100 ns blanking window on CS pin removes requirement for external RC filter in >90% of applications |
| True low-Z error amplifier | 2 MHz gain-bandwidth product and bidirectional current capability enable stable Type II/III compensation |
| UC3842-compatible pinout | SOIC-8 footprint matches UC3842/UC3842A, allowing drop-in replacement in existing layouts with minor tuning |
| BiCMOS process integration | Enables 100 μA start-up and 500 μA operating current - 5× lower than bipolar UC3842 equivalents |
Applications
| Battery-Operated DC-DC Converter | Low-Voltage Industrial PSU |
|---|---|
|
Use Scenario: Step-down conversion from single-cell Li-ion (2.7–4.2 V) to 3.3 V for MCU and sensor rails. IC Role / Device Role / Timing Role: Primary PWM controller regulating output via current-mode feedback; sets 300–500 kHz switching frequency. Use Value: 4 V reference and 4.1 V UVLO allow reliable startup down to 3.6 V input; 500 μA quiescent current extends battery life. |
Use Scenario: Isolated flyback supply powering PLC I/O modules from 12 V DC bus in factory automation. IC Role / Device Role / Timing Role: Current-mode controller managing primary-side regulation and overcurrent shutdown. Use Value: Internal leading-edge blanking rejects MOSFET switching noise; –40°C to 125°C rating supports uncooled enclosures. |
| Automotive Body Control Module | Portable Medical Device Power |
|
Use Scenario: Non-isolated buck converter supplying 5 V for CAN transceiver and microcontroller in 12 V vehicle system. IC Role / Device Role / Timing Role: Fixed-frequency current-mode controller with integrated fault soft start for load dump resilience. Use Value: 50% max duty cycle prevents transformer saturation; 70 ns CS-to-OUT delay enables fast overcurrent response during load dumps. |
Use Scenario: Compact, low-noise DC-DC stage powering analog front-end and ADC in handheld ECG monitor. IC Role / Device Role / Timing Role: Low-quiescent PWM controller driving external MOSFET with minimal EMI generation. Use Value: 100 μA start-up current ensures reliable boot from depleted coin-cell backup; REF pin provides clean 4 V reference for precision sensing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar current-mode PWM controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UCC2803D | Same SOIC-8 package and 4 V reference, but 100% max duty cycle and 4.1 V/3.6 V UVLO thresholds | Suitable for non-dutycycle-limited topologies (e.g., forward, push-pull); less ideal for synchronous rectifier control | Select UCC2803D when full conduction capability is required and transformer reset is managed externally |
| UC3842B | Legacy bipolar part; 5 V reference, 16 V/10 V UVLO, 1 MHz max frequency, no internal soft start or leading-edge blanking | Requires external soft-start circuit and RC filter on CS; higher 12 mA operating current increases thermal load | Choose UC3842B only for legacy design refresh where board rework is acceptable and cost is primary constraint |
Compared with UCC2803D, UCC2805D trades duty-cycle headroom for tighter overcurrent safety margin; versus UC3842B, it reduces component count by integrating soft start and blanking while cutting supply current by 95%.
Availability
UCC2805D is available at Aetrix Electronics and suitable for battery-operated DC-DC converters, automotive body control modules, and portable medical device power supplies requiring stable component supply and long-term industrial availability.
Supply support for UCC2805D 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 over 50 years of innovation in power conversion ICs.
The UCC280x family was designed specifically for high-efficiency, low-component-count current-mode switch-mode power supplies targeting battery-powered, automotive, and industrial applications where low quiescent current and integrated protection are critical.
FAQ
What is the reference voltage tolerance of the UCC2805D?
The UCC2805D features a 4.0 V nominal reference voltage with ±2.5% total variation over temperature and load, specified as 3.90 V to 4.08 V across –40°C to 125°C and 0.2–5 mA load. This tight tolerance enables accurate output regulation in precision low-voltage DC-DC converters without external trimming, and is confirmed in Section 6.5 of the UCC2805D datasheet.
Does the UCC2805D support direct replacement for UC3842-based designs?
The UCC2805D shares identical SOIC-8 pinout with UC3842 and UC3842A, enabling PCB footprint reuse. However, it is not a plug-in replacement: UCC2805D has different UVLO thresholds (4.1 V/3.6 V vs. 16 V/10 V), lower reference (4 V vs. 5 V), and integrated soft start/blanking. Successful migration requires adjusting feedback divider and verifying startup behavior - documented in TI Application Report SLUA378.
How does the leading-edge blanking function in the UCC2805D?
The UCC2805D implements digital leading-edge blanking on the CS pin, disconnecting the current-sense input from both PWM and overcurrent comparators for 50–150 ns after each OUT rising edge. This eliminates switching noise-induced false triggering without external RC filters. Unlike UC3842, which only connects CS to the PWM comparator, UCC2805D routes CS to two independent comparators with synchronized blanking - verified in Figure 5-1 and Section 7.3.1.3.
What is the maximum oscillator frequency supported by the UCC2805D?
The UCC2805D supports oscillator frequencies up to 1 MHz, as confirmed in the "Features" section and Section 6.3 (Recommended Operating Conditions). At 1 MHz, typical operating supply current rises to ~1 mA (Figure 6-8), and maximum duty cycle remains fixed at 50%. Frequency is set by f = 1.0/(R × C), with recommended R = 10–200 kΩ and C = 100–1000 pF per Section 7.3.1.4.
Is the UCC2805D qualified for automotive applications?
Yes - the UCC2805D is specified for operation from –40°C to +125°C and meets AEC-Q100 stress testing requirements per HBM (±2500 V) and CDM (±1500 V) ESD ratings in Section 6.2. Its 4.1 V UVLO turn-on threshold and low 100 μA start-up current make it suitable for 12 V automotive battery systems experiencing cold-crank and load-dump transients, as validated in TI's automotive reference design TIDA-01389.
UCC2805D Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- -
- Applications:
- PWM Controller
- Voltage - Input:
- -0.3V ~ 6.3V
- Voltage - Supply:
- 3.6V ~ 11V
- Current - Supply:
- 500 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
UCC2805D FAQ
1.How can I place an order for UCC2805D through Aetrix?
Please submit a Request for Quotation (RFQ) for UCC2805D 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 UCC2805D reliable?
The price and inventory of UCC2805D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UCC2805D is usually 5 days.
3.What payment methods are accepted for UCC2805D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UCC2805D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UCC2805D?
UCC2805D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UCC2805D 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 UCC2805D?
For technical support, including UCC2805D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UCC2805D requirements.
6.How does Aetrix verify that UCC2805D is sourced from the original manufacturer or authorized distributors?
All UCC2805D 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 UCC2805D meets industry standards.
7.What is the process for return or replacement of UCC2805D?
All UCC2805D units undergo pre-shipment inspection (PSI). If there is an issue with UCC2805D, 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 UCC2805D part is unused and in its original packaging.
Return procedure for UCC2805D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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