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Analog Devices Inc./Maxim Integrated MAX8538EEI+
- Part No.:
- MAX8538EEI+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Special Purpose Regulators
- Package:
- 28-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
MAX8538EEI+.pdf
- Description:
- IC REG CTRLR DDR 2OUT 28QSOP
- Quantity:
- Payment:
- Shipping:
Inventory:378
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Product details
Overview
The MAX8538EEI+ from Maxim Integrated is a dual out-of-phase synchronous buck controller designed for point-of-load (POL) DC-DC conversion in high-current digital power systems. It delivers two independent, nontracking 0.8V–3.6V outputs with up to 25A sourcing/sinking capability per channel, 1% output voltage accuracy, and 200kHz–1.4MHz adjustable switching frequency - enabling efficient, low-noise regulation for PowerPC™ and FPGA core supplies.
For engineers reviewing the MAX8538EEI+ datasheet, MAX8538EEI+ pinout, MAX8538EEI+ application, or MAX8538EEI+ equivalent, this device is selected for dual-rail POL designs requiring independent soft-start, hiccup-mode current limiting, fast transient response via 25MHz error amplifier, and robust overvoltage protection without external sense resistors.
Technical Context
The MAX8538EEI+ implements constant-frequency voltage-mode PWM control with two fully independent buck channels, each featuring high-bandwidth (25MHz) op-amp error amplifiers, programmable soft-start/soft-stop, and high-side current-sense architecture. It operates across 4.5V–23V input while maintaining forced-PWM mode for continuous conduction even at light load.
Each channel supports lossless current limiting via ILIM pins (180–220µA threshold), independent enable (EN1/EN2), open-drain power-good (POK1/POK2), and bootstrap gate-drive (BST1/BST2) for N-FETs. The internal 5V VL regulator powers all logic and drivers, with optional external PNP boost for >200mA drive capability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Topology | Dual synchronous buck (nontracking, out-of-phase) |
| Input Voltage Range | 4.5V to 23V - supports wide industrial and server supply rails |
| Output Voltage Range | 0.8V to 3.6V per channel - covers FPGA, ASIC, and microprocessor core voltages |
| Max Output Current | 25A per channel - enables single-controller solutions for high-power POL rails |
| Switching Frequency | 200kHz to 1.4MHz - adjustable via FREQ pin resistor for EMI/noise optimization |
| Reference Accuracy | ±1% over line/load/temperature - ensures tight regulation without calibration |
| Error Amplifier GBW | 25MHz - enables fast transient response and reduced output capacitance |
Pinout & Package
MAX8538EEI+ is housed in a 28-pin QSOP package (lead-free, RoHS-compliant), with exposed pad for thermal performance. Pin functions are validated per Maxim's datasheet Figure 3 and Pin Description table.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BST1, BST2 | Bootstrap supply inputs | Drive high-side N-FET gates above LX; require external flying capacitors and diodes |
| DH1, DH2 | High-side gate drivers | Swing from LX to BST; support N-FETs with <2.5Ω on-resistance |
| DL1, DL2 | Low-side gate drivers | Swing from PGND to VL; optimized for synchronous rectification |
| LX1, LX2 | Switch-node connections | Connect to inductor switches; serve as return rails for DH drivers and current sensing |
| ILIM1, ILIM2 | Current-limit programming inputs | Set lossless hiccup-mode threshold (180–220µA) for overcurrent protection |
| FB1, FB2 | Feedback inputs | Monitor output voltage against 0.8V reference; require <40kΩ impedance |
| EN1, EN2 | Independent enable inputs | Active-low logic control; allow staggered startup and rail sequencing |
| POK1, POK2 | Open-drain power-good outputs | Assert high when output is within ±12% of regulation; used for system monitoring |
Key Features
| Feature | Design Value |
|---|---|
| Out-of-phase dual-buck operation | Reduces input ripple current by ~70% vs. in-phase, lowering bulk capacitor requirements |
| Forced-PWM continuous conduction | Maintains fixed frequency under all loads - avoids audible noise and simplifies EMI filtering |
| 25MHz error amplifier bandwidth | Enables <10µs response to 5A/µs load transients - cuts required output capacitance by ≥30% |
| Lossless hiccup-mode current limit | Programmable via ILIM pins - eliminates sense resistor losses and PCB area |
| Independent soft-start/soft-stop | Prevents inrush current and voltage overshoot during power-up/down sequencing |
| Overvoltage latch-off protection | Shuts down high-side FET and latches low-side on if output exceeds +17% - prevents damage to downstream ICs |
Applications
| PowerPC™ Core Supply | FPGA I/O Bank Supply |
|---|---|
|
Use Scenario: Regulating dual-core PowerPC™ processors (e.g., MPC7447A) requiring 1.8V/15A and 2.5V/5A rails with strict sequencing. IC Role / Device Role / Timing Role: Dual-channel POL controller providing independent voltage rails, soft-start timing, and rail-ordering via EN1/EN2. Use Value: Eliminates need for two discrete controllers - reduces BOM count, layout area, and thermal coupling between rails. |
Use Scenario: Powering Xilinx Virtex-II FPGA I/O banks with 2.5V/10A and 3.3V/12A outputs under dynamic load changes. IC Role / Device Role / Timing Role: Nontracking dual-buck controller delivering stable, low-noise I/O voltage with fast transient recovery. Use Value: 25MHz error amplifier maintains <±25mV regulation during 8A step loads - meets FPGA I/O voltage tolerance specs. |
| Industrial CPU Module Supply | Network Processor SoC Supply |
|
Use Scenario: Providing 1.2V/20A and 1.8V/15A to ARM-based industrial CPU modules operating in -40°C to +85°C environments. IC Role / Device Role / Timing Role: High-reliability dual-buck controller with thermal shutdown, UVLO, and latch-off OVP. Use Value: 1% reference accuracy and -40°C to +85°C guaranteed specs ensure consistent regulation across extended temperature range. |
Use Scenario: Powering multi-core network processors (e.g., Intel IXP425) requiring tightly regulated 1.5V and 2.5V rails with fast load-step response. IC Role / Device Role / Timing Role: Out-of-phase controller minimizing input capacitor stress and improving efficiency at partial load. Use Value: >90% peak efficiency at 12V input enables compact thermal design without heatsinks in space-constrained telecom modules. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual synchronous buck controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ISL6522CRZ | Single-channel controller with external VTT tracking circuit; no integrated VTTR amplifier | Requires additional components for DDR termination supply - not suitable for MAX8538EEI+'s dual-POL use case | Select only if designing legacy DDR1 systems where VTT/VTR tracking is handled externally |
| TPS54620RGYT | Single-channel, 6A max per channel; no out-of-phase operation or hiccup-mode ILIM | Limited to lower-current applications; lacks independent EN/POK per channel | Choose only for cost-sensitive, low-power dual-rail designs where 25A capability is unnecessary |
Compared with ISL6522CRZ and TPS54620RGYT, the MAX8538EEI+ uniquely delivers dual 25A out-of-phase buck control in one 28-pin QSOP, eliminating external tracking circuitry and supporting full-system rail sequencing - making it optimal for high-density, high-current POL implementations.
Availability
MAX8538EEI+ is available at Aetrix Electronics and suitable for industrial CPU modules, FPGA power systems, networking SoC supplies, and PowerPC™ embedded platforms requiring stable component supply, long-term lifecycle support, and lead-free compliance.
Supply support for MAX8538EEI+ 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
Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, computing, and communications markets.
The MAX8537/MAX8538/MAX8539 product line was engineered specifically for DDR memory and high-current point-of-load power delivery - emphasizing precision regulation, fast transient response, and integration of dual controllers with termination reference generation.
FAQ
What is the maximum supported output current per channel for the MAX8538EEI+?
The MAX8538EEI+ supports up to 25A of sourcing or sinking current per buck channel, verified across the full -40°C to +85°C operating temperature range and confirmed in the Electrical Characteristics table under "Current-Limit Threshold" and typical operating waveforms. This rating assumes proper thermal design using the 28-pin QSOP package with adequate PCB copper area.
Does the MAX8538EEI+ support independent voltage tracking between its two outputs?
No - the MAX8538EEI+ is explicitly configured as a dual nontracking controller, unlike the MAX8537/MAX8539 which provide VTT/VTTR tracking. Its FB1 and FB2 inputs reference separate internal thresholds (both 0.8V), allowing fully independent output voltage programming from 0.8V to 3.6V without interdependence.
Can the MAX8538EEI+ operate with an input voltage below 4.5V?
No - the absolute minimum V+ operating voltage is 4.5V, as specified in the Absolute Maximum Ratings and Electrical Characteristics tables. Operation below this level risks failure to start or maintain regulation, since the internal VL regulator requires ≥4.5V input to sustain its 5V output with sufficient headroom.
What is the purpose of the AVL pin on the MAX8538EEI+?
The AVL pin on the MAX8538EEI+ is the analog VL input, connected internally to the 5V linear regulator output. It must be tied to VL through a 4.7Ω resistor and bypassed with ≥0.1µF ceramic capacitance to GND to suppress noise coupling into sensitive analog circuitry such as error amplifiers and reference buffers.
How does the MAX8538EEI+ implement overvoltage protection?
The MAX8538EEI+ implements overvoltage protection by latching off the high-side MOSFET and latching on the low-side MOSFET when the regulated output exceeds +17% of its set value - a hard fault condition that persists until reset via EN_ deassertion or power cycle. This behavior is confirmed in the Detailed Description section and protects downstream FPGAs, CPUs, and memory devices.
MAX8538EEI+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 28-SSOP (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Applications:
- Controller, DDR
- Voltage - Input:
- 4.5V ~ 23V
- Number of Outputs:
- 2
- Voltage - Output:
- 0.8V ~ 3.6V
- Operating Temperature:
- 0°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-QSOP
MAX8538EEI+ FAQ
1.How can I place an order for MAX8538EEI+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX8538EEI+ 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 MAX8538EEI+ reliable?
The price and inventory of MAX8538EEI+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX8538EEI+ is usually 5 days.
3.What payment methods are accepted for MAX8538EEI+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX8538EEI+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX8538EEI+?
MAX8538EEI+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX8538EEI+ 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 MAX8538EEI+?
For technical support, including MAX8538EEI+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX8538EEI+ requirements.
6.How does Aetrix verify that MAX8538EEI+ is sourced from the original manufacturer or authorized distributors?
All MAX8538EEI+ 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 MAX8538EEI+ meets industry standards.
7.What is the process for return or replacement of MAX8538EEI+?
All MAX8538EEI+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX8538EEI+, 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 MAX8538EEI+ part is unused and in its original packaging.
Return procedure for MAX8538EEI+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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