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Texas Instruments UC2842AQD8
- Part No.:
- UC2842AQD8
- Manufacturer:
- Texas Instruments
- Category:
- Power Supply Controllers, Monitors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
UC2842AQD8.pdf
- Description:
- IC CURR MODE PWM CONTROLLR 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:569
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Product details
Overview
UC2842AQD8 from Texas Instruments is a current-mode PWM controller IC designed for off-line and DC-DC switch-mode power supplies, featuring –40°C to 125°C operating temperature, <0.5 mA start-up current, 8.3 mA trimmed oscillator discharge current, under-voltage lockout with 16 V turn-on/10 V turn-off thresholds, and <100% maximum duty cycle. It drives external MOSFETs in flyback, forward, and boost topologies for industrial PSUs and battery-operated power systems.
For engineers reviewing the UC2842AQD8 datasheet, UC2842AQD8 pinout, UC2842AQD8 application, or UC2842AQD8 equivalent, this page delivers verified electrical characteristics, SOIC-8 package mapping, functional pin roles, real-world converter implementation context, and validated alternative options for current-mode SMPS design.
Technical Context
The UC2842AQD8 implements a fixed-frequency current-mode control architecture with a 1-MHz error amplifier, pulse-by-pulse current limiting via ISENSE input clamped at 1 V, and automatic feed-forward compensation. Its oscillator uses RT/CT pins with recommended 5 kΩ–100 kΩ resistors and 470 pF–4.7 nF capacitors to set frequency up to 500 kHz.
Internally trimmed bandgap reference (5.0 V ±1%) feeds VREF output and stabilizes error amplifier operation; UVLO hysteresis ensures clean startup above 16 V and shutdown below 10 V; output stage delivers ±1 A peak gate drive with 0.4 V low-level saturation at 200 mA sink.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Operating Temp Range | –40°C to +125°C - supports industrial and automotive-grade PSU designs without derating. |
| Start-up Current | <0.5 mA - enables high-impedance biasing from HV startup networks, reducing auxiliary supply losses. |
| Oscillator Discharge Current | 8.3 mA (typ) - sets precise timing slope for stable frequency control across temperature and voltage. |
| VREF Output Voltage | 5.0 V ±1% - provides accurate, low-noise (50 µV RMS) reference for feedback and sensing circuits. |
| UVLO Thresholds | 16 V (ON), 10 V (OFF) - ensures reliable power sequencing and brownout immunity in offline AC/DC converters. |
| Max Duty Cycle | <100% - allows full-range PWM control for flyback and forward converters without external clamp. |
| Output Drive Capability | ±1 A peak - directly drives medium-power MOSFET gates without external buffer stages. |
Pinout & Package
UC2842AQD8 is housed in an 8-pin SOIC (D) package measuring 4.90 mm × 6.00 mm, with 1.27 mm lead pitch and RoHS-compliant NiPdAu (NIPDAU) finish. It conforms to JEDEC MS-012 and TI's D0008A outline.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VFB | Error amplifier inverting input | Connects to optocoupler or resistor divider for isolated voltage feedback; sets regulation point via COMP loop. |
| ISENSE | Current sense comparator input | Monitors primary-side current via shunt; clamps at 1 V to enforce cycle-by-cycle overcurrent protection. |
| RT/CT | Oscillator timing interface | Accepts external RC network (e.g., 10 kΩ + 3.3 nF) to program switching frequency from ~47 kHz to 500 kHz. |
| GND | Signal ground reference | Common return for internal analog blocks; must be tied to power ground with low-inductance path. |
| OUTPUT | Totem-pole gate driver output | Sources/sinks ±1 A to drive N-channel MOSFET gates; requires series gate resistor for dV/dt control. |
| VCC | Supply input with internal Zener | Operates from 10–30 V; internal 39 V Zener protects against transients; bypassed with 0.1 µF + bulk capacitor. |
| VREF | 5-V reference output | Stable 5.0 V ±1% source for biasing sensors, optocouplers, or auxiliary circuits; load-limited to 20 mA. |
Key Features
| Feature | Design Value |
|---|---|
| Pulse-by-pulse current limiting | Hardware-enforced per-cycle peak current cutoff via ISENSE input, eliminating need for external fault latches. |
| Trimmed oscillator discharge current | 8.3 mA (typ) tolerance ensures ±5% frequency accuracy over temperature without external calibration. |
| High-current totem-pole output | ±1 A drive capability reduces gate charge time and enables direct drive of MOSFETs up to 1 kW level. |
| Under-voltage lockout with hysteresis | 16 V turn-on / 10 V turn-off prevents erratic operation during brownouts and ensures clean power-up sequencing. |
| Internally trimmed bandgap reference | 5.0 V ±1% output with 0.4 mV/°C drift enables precision feedback without external voltage references. |
Applications
| Industrial Switch-Mode Power Supply | Offline Flyback Converter |
|---|---|
|
Use Scenario: 95–130 VAC input, 40 kHz switching, dual-output (+5 V/4 A, ±12 V/0.3 A) industrial PSU with 3750 V isolation. IC Role / Device Role / Timing Role: Primary-side PWM controller generating gate drive signals, regulating output via optocoupler feedback, and enforcing current limit on each switching cycle. Use Value: Enables compact, high-efficiency (70% full-load) design with built-in protection, eliminating discrete current-sense amplifiers and fault logic. |
Use Scenario: Universal-input (85–265 VAC), 65 kHz flyback for consumer adapter delivering 12 V/2 A with <100 mV ripple. IC Role / Device Role / Timing Role: Current-mode controller providing stable regulation under line/load transients, slope compensation support, and UVLO-based safe startup. Use Value: Reduces component count by integrating error amp, oscillator, PWM comparator, and 1-A gate driver in SOIC-8 footprint. |
| DC-DC Boost Converter | Battery-Operated PSU |
|
Use Scenario: 12 V input boosted to 24 V/1 A for industrial sensor node, using discrete MOSFET and Schottky diode. IC Role / Device Role / Timing Role: Regulates output voltage via feedback to VFB, senses inductor current at ISENSE, and drives high-side switch with OUTPUT pin. Use Value: Delivers tight regulation (<±3%) across 10–15 V input range while maintaining >88% efficiency at full load. |
Use Scenario: Portable medical device powered from 3S Li-ion pack (9–12.6 V), requiring isolated 5 V/1 A output with low standby consumption. IC Role / Device Role / Timing Role: Low-startup-current (0.5 mA) controller enabling efficient light-load operation and fast wake-up from sleep mode. Use Value: Extends battery runtime by minimizing quiescent draw and supporting burst-mode operation below 10% load. |
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 |
|---|---|---|---|
| UC2842AD8 | Commercial temperature range (0°C to 70°C); identical pinout, oscillator, and UVLO thresholds. | Lacks extended temp rating; unsuitable for industrial or automotive environments requiring –40°C to 125°C operation. | Select UC2842AQD8 when ambient temperature exceeds 70°C or reliability under thermal stress is critical. |
| UC3842BNG | Same functional architecture but rated for 0°C to 70°C; higher start-up current (1 mA typ); no internal VREF trimming. | Lower accuracy reference (5 V ±2%) and reduced oscillator stability limit use in precision-regulated or wide-temp designs. | Choose UC2842AQD8 where tight reference tolerance, low start-up current, and extended temperature compliance are mandatory. |
Compared with UC2842AD8 and UC3842BNG, UC2842AQD8 offers superior thermal robustness, tighter reference accuracy, and lower start-up current-making it the preferred choice for mission-critical industrial and battery-powered SMPS where long-term stability and cold-start reliability matter.
Availability
UC2842AQD8 is available at Aetrix Electronics and suitable for industrial switch-mode power supplies, offline flyback converters, and battery-operated power systems requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for UC2842AQD8 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 and embedded processing technologies, with decades of expertise in power management ICs and industrial-grade signal chain solutions.
The UC284xA family was engineered specifically for cost-sensitive, high-reliability current-mode switch-mode power supplies-targeting industrial, telecom, and battery-powered applications demanding extended temperature operation and integrated protection features.
FAQ
What is the maximum switching frequency supported by UC2842AQD8?
The UC2842AQD8 supports up to 500 kHz operation, achieved by selecting appropriate RT and CT values-TI recommends RT between 5 kΩ and 100 kΩ and CT between 470 pF and 4.7 nF. At typical settings (RT = 10 kΩ, CT = 3.3 nF), the oscillator runs near 52 kHz, but frequency scales inversely with CT and linearly with RT. The UC2842AQD8 datasheet confirms 500 kHz as the absolute maximum specified limit.
Does UC2842AQD8 include an internal voltage reference?
Yes, UC2842AQD8 integrates a precision 5.0 V ±1% bandgap reference output on the VREF pin, with typical output noise of 50 µV RMS (10 Hz–10 kHz) and load regulation of ≤25 mV from 1 mA to 20 mA. This reference is internally trimmed and thermally compensated, eliminating the need for external reference ICs in most SMPS feedback networks.
What is the UVLO behavior of UC2842AQD8?
The UC2842AQD8 features under-voltage lockout with 16 V turn-on and 10 V turn-off thresholds, providing 6 V hysteresis. When VCC drops below 10 V, the OUTPUT pin disables and internal circuitry enters low-power state; re-enabling occurs only after VCC rises above 16 V. This prevents erratic operation during brownouts and ensures clean startup in offline AC/DC applications.
Can UC2842AQD8 drive MOSFETs directly without external buffers?
Yes, UC2842AQD8's OUTPUT pin delivers ±1 A peak source/sink current, enabling direct drive of medium-power N-channel MOSFETs with gate charges up to ~100 nC at typical 40–100 kHz frequencies. A series gate resistor (e.g., 10 Ω) is required to control dV/dt and suppress ringing; layout must minimize loop inductance between OUTPUT, GND, and MOSFET gate.
Is UC2842AQD8 pin-compatible with UC2842AD8?
Yes, UC2842AQD8 is pin-for-pin compatible with UC2842AD8 and all members of the UC2842A/3A/4A/5A family in the same SOIC-8 package. Both share identical pin functions, electrical interface, and PCB footprint. However, UC2842AQD8 adds extended temperature rating (–40°C to 125°C) and tighter parameter tolerances, making it a drop-in upgrade for ruggedized designs.
UC2842AQD8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Programmable:
- -
- Applications:
- PWM Controller
- Voltage - Input:
- -0.3V ~ 6.3V
- Voltage - Supply:
- 10V ~ 30V
- Current - Supply:
- 11 mA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
UC2842AQD8 FAQ
1.How can I place an order for UC2842AQD8 through Aetrix?
Please submit a Request for Quotation (RFQ) for UC2842AQD8 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 UC2842AQD8 reliable?
The price and inventory of UC2842AQD8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UC2842AQD8 is usually 5 days.
3.What payment methods are accepted for UC2842AQD8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UC2842AQD8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UC2842AQD8?
UC2842AQD8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UC2842AQD8 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 UC2842AQD8?
For technical support, including UC2842AQD8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UC2842AQD8 requirements.
6.How does Aetrix verify that UC2842AQD8 is sourced from the original manufacturer or authorized distributors?
All UC2842AQD8 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 UC2842AQD8 meets industry standards.
7.What is the process for return or replacement of UC2842AQD8?
All UC2842AQD8 units undergo pre-shipment inspection (PSI). If there is an issue with UC2842AQD8, 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 UC2842AQD8 part is unused and in its original packaging.
Return procedure for UC2842AQD8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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