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Analog Devices Inc. ADP3156JR-1.8-REEL
- Part No.:
- ADP3156JR-1.8-REEL
- Manufacturer:
- Analog Devices Inc.
- Category:
- Special Purpose Regulators
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
ADP3156JR-1.8-REEL.pdf
- Description:
- IC REG BUCK DUAL SW 1.8V 16-SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:12,500
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Product details
Overview
ADP3156JR-1.8-REEL from Analog Devices is a dual-output synchronous buck controller for desktop VRM applications, delivering 1.8 V ±1.3% at up to 7 A with active voltage positioning, constant off-time control, and integrated overvoltage crowbar protection. It drives two external N-channel MOSFETs and includes a linear regulator controller for auxiliary AGP/GTL rails.
For engineers reviewing the ADP3156JR-1.8-REEL datasheet, ADP3156JR-1.8-REEL pinout, ADP3156JR-1.8-REEL application, or ADP3156JR-1.8-REEL equivalent, key selection criteria include output accuracy (±1.3%), crowbar trip threshold (+9% to +24% VO), CT-programmable switching frequency, SO-16 package compatibility, and support for ACPI-compliant Pentium III motherboard power systems.
Technical Context
The ADP3156JR-1.8-REEL implements a current-mode, constant off-time architecture where tOFF is set by an external capacitor on the CT pin (1.8–3.2 µs typical), enabling stable operation without slope compensation. Its active voltage positioning dynamically adjusts output voltage vs. load current to optimize transient response.
It integrates dual gate drivers (DRIVE1/DRIVE2) with 120–200 ns transition times, an open-drain PWRGD output with ±5% regulation window and 500 µs response, and a crowbar circuit that activates when VO exceeds +9% to +24% of nominal and releases below ~50% VO.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 1.800 V nominal, 1.777–1.823 V over temperature - ensures core supply compliance with Pentium III VRM8.4 spec |
| Output Accuracy | ±1.3% total error (±1% setpoint + ±0.3% line/load) - meets tight CPU core voltage tolerance requirements |
| Off-Time | 1.8–3.2 µs (CT = 150 pF) - directly sets minimum switching frequency and controls ripple current magnitude |
| Crowbar Trip Point | +9% to +24% above VO - protects microprocessor from overvoltage faults without external components |
| Power Good Window | ±5% VO with 500 µs delay - provides reliable system reset signaling after stable regulation is achieved |
| Current Sense Threshold | 125–165 mV - defines peak inductor current limit and enables precise short-circuit foldback behavior |
| Driver Transition Time | 120–200 ns (CL = 7000 pF) - minimizes shoot-through risk and supports high-frequency MOSFET switching |
Pinout & Package
ADP3156JR-1.8-REEL is housed in a 16-lead SOIC (R-16A/SO-16) package with exposed pad thermal design. Pin 1–2 and 15 are no-connect; pins 3 (AGND), 9 (CT), 10 (CMP), 11 (PWRGD), 12 (VCC), 13 (DRIVE2), 14 (DRIVE1), and 16 (PGND) are functional. PGND and AGND are separate for noise isolation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 4 (SD) | Shutdown control input | Logic-high (>2.0 V) disables both drivers; internal pull-down enables default operation |
| 5 (FB) | Linear regulator feedback | Connects to resistor divider to set auxiliary output (e.g., 1.5 V for GTL) independently of main 1.8 V rail |
| 6 (VLDO) | Linear regulator gate drive | Drives external N-MOSFET for high-bandwidth auxiliary rail generation with fast load transient response |
| 7 (SENSE–) | Main output voltage sense reference | Internal resistive divider reference point; used for active voltage positioning and error amplifier input |
| 8 (SENSE+) | Main output current sense input | Differential input for current comparator; senses voltage across RSENSE to regulate peak inductor current |
Key Features
| Feature | Design Value |
|---|---|
| Active Voltage Positioning | Adjusts 1.8 V output downward under increasing load to pre-position voltage for optimal transient recovery with minimal output capacitance |
| Integrated Overvoltage Crowbar | Turns on low-side MOSFET when VO exceeds +9% to +24%, pulling output down to protect CPU without external crowbar circuitry |
| Dual N-Channel Synchronous Drivers | DRIVE1 and DRIVE2 deliver rail-to-rail swing (0–VCC) with <200 ns transitions, enabling efficient use of low-RDS(ON) logic-level MOSFETs |
| On-Board Linear Regulator Controller | Generates auxiliary voltages (e.g., 1.5 V AGP/GTL) from the 1.8 V rail using external N-MOSFET and feedback resistors |
| Constant Off-Time Architecture | Eliminates need for slope compensation; switching frequency varies only slightly with load, simplifying EMI filtering and inductor design |
Applications
| Desktop CPU Core Supply | ACPI-Compliant Standby Power |
|---|---|
Use Scenario: Providing regulated 1.8 V core voltage to Pentium III processors on ATX motherboards with dynamic VID-like load steps up to 10 A/µs. IC Role / Device Role / Timing Role: Primary synchronous buck controller managing main core rail; uses active voltage positioning to maintain regulation during rapid load transients. Use Value: Achieves <50 mV undershoot with only 1880 µF total output capacitance, reducing board area and BOM cost versus voltage-mode alternatives. | Use Scenario: Supporting GTL and AGP interface rails during S3/S4 sleep states using the ADP3156JR-1.8-REEL's integrated linear regulator controller. IC Role / Device Role / Timing Role: Auxiliary linear regulator driver generating 1.5 V from the 1.8 V main rail; operates with high bandwidth to suppress cross-rail transients. Use Value: Eliminates need for separate LDO ICs while maintaining <1% static error and sub-10 µs response to 1 A load steps on auxiliary rail. |
| VRM8.4 Reference Design | Northbridge/Southbridge Power |
Use Scenario: Implementing Intel VRM8.4-compliant power delivery in reference designs for chipset evaluation and BIOS validation. IC Role / Device Role / Timing Role: Dual-output controller satisfying VRM8.4 accuracy (±1.3%), crowbar (+15% trip), and PWRGD timing (500 µs) requirements. Use Value: Enables single-chip compliance with full VRM8.4 specification - including active positioning, crowbar, and power-good - without external comparators or timers. | Use Scenario: Supplying 1.8 V to Northbridge logic and memory controllers while simultaneously powering Southbridge I/O via the VLDO-controlled linear stage. IC Role / Device Role / Timing Role: Central power management IC coordinating primary switching and auxiliary linear regulation for multi-rail chipset subsystems. Use Value: Reduces component count by integrating both functions; separates transient domains so 1.5 V I/O activity does not degrade 1.8 V core stability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ISL6522CRZ | Fixed 1.8 V output; uses voltage-mode control with slope compensation; no active voltage positioning | Lacks built-in crowbar; requires external overvoltage protection; lower transient performance with same output capacitance | Preferred where cost sensitivity outweighs transient performance; suitable for non-VRM legacy designs |
| TPS51100PWR | Supports 1.8 V output but requires external VID interface; includes integrated MOSFET drivers with programmable dead time | Designed for mobile VRM; lacks crowbar function; optimized for lower quiescent current in battery-backed standby | Better fit for portable platforms; less suitable for desktop VRM8.4 compliance due to missing crowbar and AVP |
Compared with ISL6522CRZ and TPS51100PWR, ADP3156JR-1.8-REEL delivers superior transient response via active voltage positioning and eliminates external crowbar components - critical for Pentium III desktop reliability - while maintaining SO-16 footprint compatibility.
Availability
ADP3156JR-1.8-REEL is available at Aetrix Electronics and suitable for desktop motherboard power supplies, VRM8.4 reference designs, and ACPI-compliant chipset power systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for ADP3156JR-1.8-REEL 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
Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, communications, and power management markets.
The ADP3156 product line was designed specifically for Intel VRM-compliant desktop CPU core power delivery, emphasizing active voltage positioning, integrated protection, and dual-output capability for Pentium III-era motherboards.
FAQ
What is the output voltage tolerance of the ADP3156JR-1.8-REEL over temperature and line conditions?
The ADP3156JR-1.8-REEL guarantees a total output voltage tolerance of ±1.3% across temperature (0°C to +70°C) and input line variation (VIN = 4.75 V to 5.25 V). This is derived from ±0.3% line regulation and ±1.0% setpoint accuracy (1.777 V to 1.823 V), meeting VRM8.4 requirements for Pentium III core supplies. The ADP3156JR-1.8-REEL achieves this without external trimming components.
Does the ADP3156JR-1.8-REEL support active voltage positioning, and how does it improve transient response?
Yes, the ADP3156JR-1.8-REEL implements active voltage positioning (AVP) by dynamically lowering the 1.8 V output as load current increases. This pre-positions the voltage to minimize undershoot during sudden load steps - achieving <50 mV deviation with only 1880 µF output capacitance. AVP is integral to the ADP3156JR-1.8-REEL's error amplifier and current comparator architecture, eliminating need for external compensation networks.
What is the crowbar protection behavior of the ADP3156JR-1.8-REEL, and at what voltage does it activate?
The ADP3156JR-1.8-REEL crowbar activates when the output voltage exceeds +9% to +24% of nominal (i.e., 1.96–2.23 V for 1.8 V output), turning on the low-side MOSFET to clamp the rail. It releases when VO falls below ~50% of nominal (~0.9 V). This protection is fully integrated - no external components required - and is a defining feature of the ADP3156JR-1.8-REEL for CPU core safety.
Can the ADP3156JR-1.8-REEL generate auxiliary voltages, and how is that configured?
Yes, the ADP3156JR-1.8-REEL includes a dedicated linear regulator controller (VLDO pin) to generate auxiliary rails like 1.5 V for GTL or AGP. It uses an external N-channel MOSFET and resistor divider on FB pin to set the output. For example, with R1 = 5 kΩ and R2 = 20 kΩ, the ADP3156JR-1.8-REEL delivers 1.47–1.53 V at 1 A with <1% error - all managed internally without additional ICs.
What package and pin-compatible alternatives exist for the ADP3156JR-1.8-REEL in SO-16 format?
The ADP3156JR-1.8-REEL uses a standard 16-lead SOIC (R-16A/SO-16) package with defined pinout per Analog Devices datasheet Rev. 0. While ISL6522CRZ shares the SO-16 footprint, it is not pin-compatible due to different FB/SENSE/CT assignments and lacks AVP and crowbar. No documented pin-to-pin replacement exists; migration requires PCB layout revision and firmware validation. The ADP3156JR-1.8-REEL's pin mapping is unique to its functional block diagram.
ADP3156JR-1.8-REEL Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Applications:
- Controller, Intel Pentium® III
- Voltage - Input:
- 3V, 5V
- Number of Outputs:
- -
- Voltage - Output:
- 1.8V
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
ADP3156JR-1.8-REEL FAQ
1.How can I place an order for ADP3156JR-1.8-REEL through Aetrix?
Please submit a Request for Quotation (RFQ) for ADP3156JR-1.8-REEL 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 ADP3156JR-1.8-REEL reliable?
The price and inventory of ADP3156JR-1.8-REEL are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ADP3156JR-1.8-REEL is usually 5 days.
3.What payment methods are accepted for ADP3156JR-1.8-REEL?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ADP3156JR-1.8-REEL transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ADP3156JR-1.8-REEL?
ADP3156JR-1.8-REEL orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ADP3156JR-1.8-REEL 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 ADP3156JR-1.8-REEL?
For technical support, including ADP3156JR-1.8-REEL datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ADP3156JR-1.8-REEL requirements.
6.How does Aetrix verify that ADP3156JR-1.8-REEL is sourced from the original manufacturer or authorized distributors?
All ADP3156JR-1.8-REEL 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 ADP3156JR-1.8-REEL meets industry standards.
7.What is the process for return or replacement of ADP3156JR-1.8-REEL?
All ADP3156JR-1.8-REEL units undergo pre-shipment inspection (PSI). If there is an issue with ADP3156JR-1.8-REEL, 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 ADP3156JR-1.8-REEL part is unused and in its original packaging.
Return procedure for ADP3156JR-1.8-REEL:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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