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Diodes Incorporated PAM2421AECADJR
- Part No.:
- PAM2421AECADJR
- Manufacturer:
- Diodes Incorporated
- Package:
- 8-SOIC (0.154", 3.90mm Width) Exposed Pad
- Datasheet:
-
PAM2421AECADJR.pdf
- Description:
- IC REG BOOST ADJ 3A 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:2,060
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Product details
Overview
PAM2421AECADJR from Diodes Incorporated is a 3A peak-current, fixed-frequency (520kHz), current-mode PWM step-up DC-DC converter with integrated 24V power MOSFET, internal OVP, programmable soft-start, and SOP-8(EP) packaging-designed for TFT LCD bias supplies in portable monitors requiring compact, high-efficiency boost conversion from 2.7–5.5V input to up to 24V output.
For engineers reviewing the PAM2421AECADJR datasheet, PAM2421AECADJR pinout, PAM2421AECADJR application, or PAM2421AECADJR equivalent, key selection criteria include verified 1.262V FB reference accuracy, 85% max duty cycle, thermal shutdown at 160°C, under-voltage lockout at 2.5V, and SOP-8(EP) thermal resistance (θJA = 180°C/W).
Technical Context
This device implements a nonsynchronous, current-mode PWM architecture with pulse-skipping at light loads to maintain efficiency across wide load ranges. It regulates output voltage via a resistive divider on the FB pin referenced to a precise 1.262V internal bandgap.
Control logic includes EN-driven enable/disable with 0.4V/1.4V logic thresholds, active SS pin discharge during shutdown, and cycle-by-cycle current limiting tied to SW node conduction. Protection functions are fully autonomous: OVP triggers at 115% of nominal output, open-loop detection disables regulation when FB < 0.2V, and thermal shutdown re-enables after 40°C hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Switch Current | 3A - sets maximum inductor peak current and defines minimum inductor saturation rating required for stable operation. |
| Switching Frequency | 520kHz - determines size of external inductor and output capacitor; enables compact layout with minimal EMI filtering. |
| FB Reference Voltage | 1.262V ±25mV - defines output voltage accuracy when using external resistor divider; enables 24V max output with <±1% regulation error. |
| UVLO Threshold | 2.5V rising - prevents startup until input rail is sufficiently above dropout; ensures reliable gate drive for internal MOSFET. |
| Thermal Shutdown | 160°C with 40°C hysteresis - protects die from permanent damage during sustained overload or poor PCB heatsinking. |
| OVP Activation | 115% of regulated output - clamps output by disabling switching before external components exceed voltage ratings. |
| Efficiency | >90% - reduces thermal load in space-constrained applications such as handheld displays and set-top boxes. |
Pinout & Package
SOP-8(EP) package with exposed thermal pad soldered to PCB ground plane for enhanced thermal dissipation (θJC = 75°C/W, θJA = 180°C/W).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 PGND | Power Ground | Low-impedance return path for high di/dt switch current; must be connected directly to exposed pad and input capacitor ground. |
| 2 IN | Supply Input | Primary DC input (2.7–5.5V); connects to bulk input capacitor and feeds internal bias circuitry and power MOSFET source. |
| 3 EN | Enable Control | Logic-level input (0.4V low / 1.4V high threshold); floating not allowed-tie to IN if unused. |
| 4 COMP | Error Amplifier Compensation Node | Connects external RC network to stabilize control loop; determines transient response and phase margin. |
| 5 AGND | Analog Ground | Reference for FB, COMP, and SS; must be star-connected near IC to minimize noise coupling into feedback path. |
| 6 FB | Feedback Input | Senses output via resistor divider; regulated to 1.262V-output = 1.262V × (1 + R1/R2). |
| 7 SS | Soft-Start Control | Capacitor-to-ground sets startup ramp time; 10nF yields ~22ms soft-start; discharged during shutdown. |
| 8 SW | Switch Output | Drives external Schottky diode and inductor; high dv/dt node-requires short, low-inductance trace to input cap. |
| Exposed PAD | Thermal & Electrical Ground | Must be soldered to solid copper pour tied to PGND for thermal performance and EMI reduction. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 24V Power MOSFET | Eliminates external high-voltage switch; supports 24V output without level-shifting or external driver. |
| Programmable Soft-Start | External capacitor sets controlled output ramp-prevents inrush into large output capacitors and downstream LDOs. |
| Open-Loop Protection | Auto-shutdown when FB < 0.2V-prevents unregulated high-voltage output during feedback disconnection or divider fault. |
| Internal Over-Voltage Protection | Hardware-based clamp at 115% output-acts independently of control loop timing for fail-safe response. |
| Pulse-Skipping Light-Load Mode | Maintains >85% efficiency at 1mA load-critical for battery-powered standby operation in modems and routers. |
Applications
| TFT LCD Bias Supply | Battery-Powered Portable Monitor |
|---|---|
Use Scenario: Generating 18–24V bias rails for TFT panel gate drivers and source drivers from single-cell Li-ion (3.0–4.2V) or USB 5V input. IC Role / Device Role / Timing Role: Primary step-up regulator with fixed 520kHz PWM frequency and current-mode control ensuring fast transient response to pixel column switching loads. Use Value: 92% peak efficiency minimizes heat in sealed display enclosures; SOP-8(EP) footprint allows placement near panel connector with minimal trace length. | Use Scenario: Powering dual-rail analog front-end and backlight LED driver in handheld medical or industrial display units operating from 2-cell alkaline or LiPo batteries. IC Role / Device Role / Timing Role: Main DC-DC boost stage enabling consistent 24V output across full battery discharge curve (2.7–5.5V input range). Use Value: UVLO at 2.5V prevents brownout-induced display flicker; thermal shutdown protects against enclosure overheating during extended operation. |
| DSL/Cable Modem Power Rail | Set-Top Box Tuner Supply |
Use Scenario: Providing isolated 12–24V supply for RF front-end amplifiers and line-driver ICs in broadband access equipment with strict EMI limits. IC Role / Device Role / Timing Role: Nonsynchronous boost converter with minimized SW node ringing; 520kHz frequency avoids critical ISM bands (e.g., 2.4GHz harmonics). Use Value: Integrated OVP and cycle-by-cycle current limit prevent damage during cable surge events or short-circuit faults on RF output lines. | Use Scenario: Delivering stable 18V rail to satellite tuner modules requiring low-noise, tightly regulated voltage independent of main 12V system rail fluctuations. IC Role / Device Role / Timing Role: Secondary regulated boost stage with FB pin referenced to precision 1.262V bandgap-rejects input ripple via high PSRR control loop. Use Value: 0.15%/V line regulation ensures <±30mV output shift over 12V ±10% input variation-maintains tuner LO stability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-up DC-DC converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS61088RHLR | Higher 5.5A peak current, 2.7–12V input, integrated synchronous rectifier, 500kHz–2.2MHz adjustable frequency. | Supports wider input range and higher output current; requires external compensation but offers better light-load efficiency via DCM mode. | Select when >3A output current or synchronous rectification for lower conduction loss is required. |
| RT8535GJ6F | 3A peak current, 2.5–5.5V input, 1.215V FB reference, 1.3MHz fixed frequency, smaller SOT-23-6 package. | Limited to ≤15V output due to 16V MOSFET rating; higher switching frequency reduces inductor size but increases EMI filtering complexity. | Select when board space is constrained and output ≤15V suffices; avoid for 24V TFT bias due to voltage margin risk. |
Compared with TPS61088RHLR and RT8535GJ6F, PAM2421AECADJR provides optimal balance of 24V capability, thermal robustness in SOP-8(EP), and cost-effective nonsynchronous design-making it preferred for fixed 24V bias generation where synchronous efficiency gains are secondary to voltage headroom and layout simplicity.
Availability
PAM2421AECADJR is available at Aetrix Electronics and suitable for TFT LCD bias supplies, battery-powered portable monitors, and DSL/cable modem RF power rails requiring stable component supply, long-term lifecycle support, and RoHS-compliant tape-and-reel packaging (2500 units per reel).
Supply support for PAM2421AECADJR 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.
The PAM242x product line targets compact, high-efficiency boost conversion in space-constrained applications-specifically engineered for TFT LCD bias, portable display, and broadband communications equipment requiring reliable 24V output from low-input sources.
FAQ
What input voltage range does PAM2421AECADJR support?
The PAM2421AECADJR operates from 2.7V to 5.5V input, with under-voltage lockout activating below 2.5V (200mV hysteresis). This range supports single-cell Li-ion (3.0–4.2V), USB 5V, and two-cell alkaline (2.7–3.6V) sources-ensuring compatibility with common portable power architectures without external LDO pre-regulation.
How is output voltage set, and what is the FB reference accuracy?
Output voltage is set externally using a resistor divider from VOUT to FB to GND, with FB regulated to 1.262V (±25mV over temperature). The equation is VOUT = 1.262V × (1 + R1/R2). This reference tolerance directly contributes to output accuracy-e.g., with 1% resistors, total output error remains within ±1.5% across line, load, and temperature.
Does PAM2421AECADJR require an external Schottky diode, and why?
Yes-an external Schottky diode is mandatory between SW and VOUT. The IC integrates only the high-side MOSFET; the diode provides the return path for inductor current during the off-time. Diode selection must handle both peak switch current (3A) and output voltage (up to 24V), with low forward voltage (≤0.5V) to preserve efficiency and minimize thermal stress.
What protection features are implemented, and how do they behave during fault conditions?
PAM2421AECADJR includes cycle-by-cycle current limit (3A), thermal shutdown (160°C), over-voltage protection (115% output), open-loop detection (FB < 0.2V), and UVLO (2.5V). During over-current, switching pauses until next cycle; OVP forces immediate shutdown; thermal shutdown holds off until die cools by 40°C; open-loop fault disables regulation until EN is cycled.
PAM2421AECADJR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Up
- Output Configuration:
- Positive
- Topology:
- Boost
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2.7V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 2.7V
- Voltage - Output (Max):
- 24V
- Current - Output:
- 3A (Switch)
- Frequency - Switching:
- 520kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SO-EP
PAM2421AECADJR FAQ
1.How can I place an order for PAM2421AECADJR through Aetrix?
Please submit a Request for Quotation (RFQ) for PAM2421AECADJR 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 PAM2421AECADJR reliable?
The price and inventory of PAM2421AECADJR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for PAM2421AECADJR is usually 5 days.
3.What payment methods are accepted for PAM2421AECADJR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for PAM2421AECADJR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for PAM2421AECADJR?
PAM2421AECADJR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your PAM2421AECADJR 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 PAM2421AECADJR?
For technical support, including PAM2421AECADJR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your PAM2421AECADJR requirements.
6.How does Aetrix verify that PAM2421AECADJR is sourced from the original manufacturer or authorized distributors?
All PAM2421AECADJR 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 PAM2421AECADJR meets industry standards.
7.What is the process for return or replacement of PAM2421AECADJR?
All PAM2421AECADJR units undergo pre-shipment inspection (PSI). If there is an issue with PAM2421AECADJR, 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 PAM2421AECADJR part is unused and in its original packaging.
Return procedure for PAM2421AECADJR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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