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NXP Semiconductors MC34701EK
- Part No.:
- MC34701EK
- Manufacturer:
- NXP Semiconductors
- Category:
- Special Purpose Regulators
- Package:
- 32-BSSOP (0.295", 7.50mm Width)
- Datasheet:
-
MC34701EK.pdf
- Description:
- IC REG CONV QUICC 1OUT 32SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,232
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Product details
Overview
MC34701EK from Freescale Semiconductor is a dual-output switch-mode power supply IC integrating a 1.5A synchronous buck regulator for microprocessor core voltage and an I²C-programmable LDO controller for I/O/bus voltage. It operates from 2.8V–6.0V input, delivers precise 0.8V ±2% feedback reference for both outputs, supports 300kHz default switching frequency, and enables up/down power sequencing for Power QUICC I/II and MPC8xxx processors in embedded telecom and industrial control systems.
For engineers reviewing the MC34701EK datasheet, MC34701EK pinout, MC34701EK application, or MC34701EK equivalent, this page provides verified technical context on its dual-regulator architecture, I²C voltage margining, thermal shutdown (170°C), programmable reset delay, and integrated MOSFET drivers - all critical for CPU power integrity design and BOM validation.
Technical Context
The MC34701EK implements a synchronous buck converter with integrated high-side (60 mΩ) and low-side (65 mΩ) N-channel MOSFETs, driven by a 300 kHz oscillator adjustable via external resistor (200–400 kHz range). Its error amplifier features 80 dB open-loop gain and 35 MHz GBW to support fast transient response under dynamic CPU load.
It integrates a dedicated LDO control loop with linear compensation (LCMP), current-sense protection (CS/LDO pins), and gate drive (LDRV) for an external N-channel pass MOSFET. Power sequencing is determined by EN1/EN2 logic states, while I²C interface (SDA/SCL) enables real-time voltage margining and watchdog configuration.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.8 V to 6.0 V - supports single-supply operation from common intermediate rails (e.g., 3.3 V or 5 V). |
| Buck Output Current | 1.5 A continuous - sufficient for core supply of Power QUICC II and MPC82xx processors. |
| Feedback Reference Voltage | 0.800 V ±2% - enables precise core voltage regulation (e.g., 1.2 V via resistive divider) with minimal drift over temperature. |
| Switching Frequency | 300 kHz default (200–400 kHz adjustable) - balances efficiency, EMI, and inductor size for compact board layout. |
| I²C Interface | Standard-mode (100 kHz) - allows runtime voltage margining, watchdog setup, and address selection (ADDR pin). |
| Thermal Shutdown Threshold | 170 °C typical - protects internal MOSFETs and external LDO FET during overload or poor heatsinking. |
| Power Sequencing Control | EN1/EN2 logic-selectable modes - ensures safe core-I/O voltage ramp order per CPU requirements (e.g., VDDI before VDDH). |
Pinout & Package
MC34701EK is housed in a 32-pin SOICW (Wide-body Small Outline Integrated Circuit) package with exposed thermal pad, optimized for thermal dissipation in high-current DC/DC applications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| FREQ | Oscillator frequency select | Connect external resistor (7–22 kΩ) to set switching frequency from 200–400 kHz; open = 300 kHz default. |
| VOUT | Buck output voltage sense | Feedback node for core voltage regulation; connects to resistor divider output for closed-loop control. |
| VIN2 | Buck input power rail | High-current path for buck regulator input (drain of internal high-side MOSFET); requires low-impedance PCB routing. |
| SW | Switching node | Connection point between internal MOSFETs and external inductor; carries high di/dt and must be minimized in loop area. |
| VBST | Boost regulator output | 7.75 V nominal supply for gate drivers; powers internal HS/LS drivers and external LDO FET gate drive (LDRV). |
| LDRV | LDO gate driver output | Drives gate of external N-channel LDO pass transistor; requires low-ESR bootstrap capacitor at BOOT pin. |
| CS | LDO current sense input | Detects voltage drop across external sense resistor (RS) between CS and LDO pins to enable programmable overcurrent protection. |
| RST | Open-drain reset output | Active-low signal indicating fault on either VOUT or VLDO; requires external pull-up to monitored rail (e.g., LDO output). |
| SDA/SCL | I²C bidirectional bus | Enable real-time voltage margining, watchdog timer programming, and device address configuration (ADDR pin). |
Key Features
| Feature | Design Value |
|---|---|
| Precise dual-regulator feedback | 0.800 V ±2% reference for both buck and LDO loops ensures tight core/I/O voltage tolerance (<±1%) under load and temperature variation. |
| Programmable power sequencing | Four EN1/EN2 logic combinations configure standard/inverted/no sequencing - eliminates need for external timing components in CPU power-up coordination. |
| I²C voltage margining | ±7.9% adjustment range in 1% steps allows in-system validation of CPU voltage margins without hardware changes. |
| Integrated MOSFET drivers | Internal HS/LS buck drivers + LDRV output eliminate external gate drivers, reducing component count and layout complexity for compact designs. |
| Thermal and overcurrent protection | 170°C junction shutdown with 10°C hysteresis and current-limited LDO (via CS pin) prevent damage during sustained overload or short-circuit conditions. |
Applications
| Base Station Control Unit | Industrial PLC CPU Module |
|---|---|
Use Scenario: Power management for Freescale MPC8272-based base station control cards requiring stable 1.2 V core and 3.3 V I/O rails under variable RF processing loads. IC Role / Device Role / Timing Role: MC34701EK provides synchronized core/I/O power sequencing, fast transient response to burst-mode DSP activity, and I²C-adjustable voltage margins for field calibration. Use Value: Eliminates discrete sequencing ICs and reduces BOM count by integrating buck + LDO control + protection in one SOICW package. | Use Scenario: Embedded CPU power solution in DIN-rail mounted PLCs where ambient temperature exceeds 70°C and long-term reliability is critical. IC Role / Device Role / Timing Role: MC34701EK delivers regulated 1.5 V core and 2.5 V I/O voltages with thermal shutdown (170°C) and undervoltage lockout (1.6 V start-up) for robust operation in harsh environments. Use Value: Internal boost regulator (VBST = 7.75 V) ensures strong gate drive for external LDO FETs even at low input voltage, maintaining dropout performance. |
| Telecom Line Card | Network Router Management Processor |
Use Scenario: Powering Power QUICC II processors in carrier-grade line cards with strict power-good timing and fault reporting requirements. IC Role / Device Role / Timing Role: MC34701EK generates active-low RST signal only after both VOUT and VLDO stabilize and RT timer expires, meeting CPU reset timing specs. Use Value: Programmable RT pin (10 ms + R×C delay) enables precise reset assertion window matching processor specifications without external timers. | Use Scenario: Supplying Freescale MPC83xx management processors in multi-slot routers where firmware updates require voltage margining verification. IC Role / Device Role / Timing Role: MC34701EK uses I²C interface to adjust core voltage ±5% during firmware validation, confirming system stability at edge-case operating points. Use Value: Margining resolution of 1% and ±7.9% range allow granular testing of CPU voltage sensitivity without hardware rework. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-output CPU power supply applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS51116PWR | Single-chip dual-output buck controller (no integrated LDO driver); requires external MOSFETs for both rails; no I²C margining. | Targeted at Intel Pentium M/Core platforms; lacks native Power QUICC sequencing logic and LDO gate drive. | Choose when designing for x86 platforms with separate LDO requirements and higher current (>2 A) needs. |
| ISL6264CRZ | Triple-output buck controller with integrated MOSFETs; supports 3-phase core rail but no LDO controller or I²C interface. | Designed for AMD mobile CPUs; lacks linear regulator control circuitry and voltage margining capability. | Prefer for high-performance laptop CPU designs needing multiphase core regulation, not embedded Power QUICC systems. |
Compared with TPS51116PWR and ISL6264CRZ, the MC34701EK uniquely integrates synchronous buck + LDO gate drive + I²C margining + Power QUICC-specific sequencing in one SOICW package, making it irreplaceable for legacy Freescale processor designs requiring minimal external components and guaranteed compatibility.
Availability
MC34701EK is available at Aetrix Electronics and suitable for base station control units, industrial PLC CPU modules, telecom line cards, and network router management processors requiring stable component supply and long-term obsolescence support.
Supply support for MC34701EK 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
Freescale Semiconductor (now part of NXP Semiconductors) is a fabless semiconductor company specializing in embedded processing, analog, and power management solutions for automotive, industrial, and networking markets.
The MC34701EK belongs to Freescale's Power Management IC product line, designed specifically to simplify power delivery for Power QUICC and MPC8xxx microprocessors with integrated sequencing, protection, and digital configurability.
FAQ
What is the default switching frequency of the MC34701EK and how is it adjusted?
The MC34701EK has a default switching frequency of 300 kHz when the FREQ pin is left open or tied to VDDI. Frequency is adjusted using an external resistor (RF) connected from FREQ to ground: 7.0 kΩ yields ~400 kHz, 22 kΩ yields ~200 kHz, and values between 7–22 kΩ provide linear scaling across the 200–400 kHz range. This adjustment enables optimization of efficiency, EMI, and magnetics size for the target application.
How does the MC34701EK implement power sequencing for Power QUICC processors?
The MC34701EK implements power sequencing through logic-controlled EN1 and EN2 inputs. Four combinations define modes: (0,0) disables regulators; (0,1) enables standard sequencing (VOUT before VLDO); (1,0) enables inverted sequencing (VLDO before VOUT); and (1,1) enables both regulators simultaneously without sequencing. This eliminates external RC timers and matches Freescale CPU power-up requirements directly in silicon.
Can the MC34701EK regulate both core and I/O voltages independently?
Yes, the MC34701EK regulates both voltages independently: the synchronous buck converter delivers the core voltage (e.g., 1.2 V) with 0.800 V ±2% feedback reference, while the LDO controller manages I/O voltage (e.g., 3.3 V) using external N-channel MOSFET and resistive feedback via LFB pin. Each loop has separate compensation (LCMP), current sensing (CS), and gate drive (LDRV), enabling independent tuning and protection.
What protection features does the MC34701EK include?
The MC34701EK includes under-voltage lockout (1.6 V start-up threshold), overcurrent protection on both buck (ILIMH = –2.7 A) and LDO (CS/LDO current sense) paths, thermal shutdown at 170°C with 10°C hysteresis, and reset monitoring of both VOUT and VLDO outputs with 20 µs noise filtering. These features ensure robust operation during input brownouts, load faults, or thermal stress without external supervision circuits.
Is the MC34701EK compatible with modern I²C buses and what functions does it support?
Yes, the MC34701EK supports standard-mode I²C (up to 100 kHz) on SDA/SCL pins. It uses the interface for voltage margining (±7.9% in 1% steps), programmable watchdog timer setup, reset delay configuration, and device addressing (via ADDR pin). All I²C operations comply with Philips I²C specification, enabling integration into existing system management buses without protocol translation.
MC34701EK Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- -
- Package/Case:
- 32-BSSOP (0.295", 7.50mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Applications:
- Converter, Freescale Power QUICC™ I, II
- Voltage - Input:
- 2.8V ~ 6V
- Number of Outputs:
- 1
- Voltage - Output:
- Adjustable
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-SOIC
MC34701EK FAQ
1.How can I place an order for MC34701EK through Aetrix?
Please submit a Request for Quotation (RFQ) for MC34701EK 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 MC34701EK reliable?
The price and inventory of MC34701EK are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC34701EK is usually 5 days.
3.What payment methods are accepted for MC34701EK?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC34701EK transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC34701EK?
MC34701EK orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC34701EK 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 MC34701EK?
For technical support, including MC34701EK datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC34701EK requirements.
6.How does Aetrix verify that MC34701EK is sourced from the original manufacturer or authorized distributors?
All MC34701EK 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 MC34701EK meets industry standards.
7.What is the process for return or replacement of MC34701EK?
All MC34701EK units undergo pre-shipment inspection (PSI). If there is an issue with MC34701EK, 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 MC34701EK part is unused and in its original packaging.
Return procedure for MC34701EK:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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