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Microchip Technology MIC2172YN
- Part No.:
- MIC2172YN
- Manufacturer:
- Microchip Technology
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
MIC2172YN.pdf
- Description:
- IC REG BOOST CUK ADJ 1.25A 8PDIP
- Quantity:
- Payment:
- Shipping:
Inventory:667
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Product details
Overview
MIC2172YN from Microchip Technology is a 100 kHz current-mode PWM controller IC with integrated 65 V / 1.25 A NPN power switch, designed for step-up (boost), step-down, inverting, and isolated DC-DC topologies. It operates from 3 V to 40 V input, delivers up to 50 W with external switch, features external frequency synchronization and trim, and supports master/slave configurations in multi-regulator systems - used in laptop power supplies and handheld instrument converters.
For engineers reviewing the MIC2172YN datasheet, MIC2172YN pinout, MIC2172YN application, or MIC2172YN equivalent, key selection considerations include its 100 kHz fixed oscillator (adjustable to 135 kHz), SYNC input for noise-sensitive multi-rail designs, dual power ground pins (PGND1/PGND2) enabling current limit scaling, and compatibility with LT1172 sockets in boost implementations.
Technical Context
The MIC2172YN implements current-mode control using an internal transconductance error amplifier (3.9 μA/mV typical gain), cycle-by-cycle current limiting, and a 100 kHz oscillator synchronized via falling-edge–triggered SYNC input. Its floating switch architecture allows flexible topology support including boost, buck, Cuk, and flyback with external components.
It integrates a precision 1.24 V bandgap reference, anti-saturation diode for extended duty cycle, and dual emitter-ground paths (PGND1 and PGND2) - where leaving PGND1 open halves the current limit. The COMP pin serves dual roles: loop compensation and soft-start/current-limit tailoring.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switch Rating | 65 V breakdown voltage, 1.25 A continuous current limit - enables direct use in ≤50 W off-line boost converters without external switch. |
| Oscillator Frequency | 100 kHz nominal (88–112 kHz over temp), adjustable to 135 kHz via SYNC-to-GND resistor - eliminates audible beat frequencies in multi-regulator systems. |
| Input Voltage Range | 3.0 V to 40 V operating range - supports wide-input battery-powered and industrial supply rails. |
| Quiescent Current | 7 mA typical operating IQ - ensures high efficiency in low-power portable applications. |
| Feedback Reference | 1.24 V ±24 mV precision bandgap reference - sets output voltage accuracy in resistive divider feedback networks. |
| Max Duty Cycle | 89% typical - supports high step-up ratios (e.g., 5 V → 12 V) while maintaining stable current-mode operation. |
| Thermal Range | –40°C to +85°C ambient - validated for industrial and portable equipment environments. |
Pinout & Package
The MIC2172YN is housed in an 8-pin plastic DIP (N-suffix) package with through-hole mounting and 0.3 inch width. Thermal resistance θJA = 130°C/W enables operation up to +85°C ambient at moderate load.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (SGND) | Signal Ground | Analog reference ground for error amplifier and feedback circuitry - must be connected directly to input capacitor ground and kept separate from power grounds. |
| 2 (COMP) | Error Amplifier Output | Transconductance-type output used for loop compensation, soft-start timing, and current limit adjustment - high-impedance node requiring RC network to FB or GND. |
| 3 (FB) | Inverting Feedback Input | Connects to resistive divider from output - regulates output voltage by comparing against 1.24 V internal reference. |
| 4 (SYNC) | Frequency Synchronization Input | Capacitively coupled input accepting external clock >100 kHz; falling edge locks oscillator - enables master/slave coordination across multiple MIC2172YN regulators. |
| 5 (VIN) | Power Supply Input | Primary bias rail (3–40 V); powers internal regulator, oscillator, and drivers - minimum start-up voltage is 2.7 V. |
| 6 (PGND2) | Power Ground #2 | Emitter connection of internal NPN switch with 0.3 Ω sense resistor - required connection point for inductor or input ground in boost/buck topologies. |
| 7 (VSW) | Switch Collector | High-side collector of internal NPN transistor - connects to inductor (boost), transformer primary (flyback), or output diode anode. |
| 8 (PGND1) | Power Ground #1 | Second emitter path with parallel 0.3 Ω sense resistor - optional; floating reduces current limit by 2×, connecting to PGND2 restores full 1.25 A capability. |
Key Features
| Feature | Design Value |
|---|---|
| External Frequency Sync | Enables precise phase alignment of multiple MIC2172YN regulators to eliminate beat frequencies in multi-rail systems - critical for EMI-sensitive portable electronics. |
| Dual Power Ground Pins | PGND1 and PGND2 allow scalable current limiting: floating PGND1 cuts max switch current to ~0.625 A, simplifying design for lower-power applications without component changes. |
| Current-Mode Control | Provides inherent cycle-by-cycle current limiting, simplified loop compensation (removes LC double pole), and automatic input voltage feed-forward - improves transient response and stability across line/load variations. |
| Anti-Saturation Diode | Reduces Q1 base-collector stored charge, extending usable duty cycle beyond 89% - essential for high-ratio boost conversion (e.g., 5 V → 12 V). |
| LT1172 Socket Compatibility | Pinout matches LT1172 DIP footprint - enables drop-in replacement in legacy designs with minimal layout change, accelerating upgrade paths for aging power supplies. |
Applications
| Laptop/Palmtop Power Supply | Handheld Instrument DC-DC Conversion |
|---|---|
Use Scenario: Generating regulated 12 V from a 5 V logic rail in compact portable computers. IC Role / Device Role / Timing Role: Primary current-mode PWM controller with integrated 65 V/1.25 A switch, managing boost topology switching at 100 kHz. Use Value: Eliminates need for external MOSFET driver and high-voltage switch, reducing BOM count and PCB area while maintaining <1% output regulation under dynamic load. | Use Scenario: Providing isolated 5 V output from 4–6 V battery input in portable test equipment. IC Role / Device Role / Timing Role: Flyback controller with floating switch architecture, using VSW and PGND2 as primary-side switch terminals. Use Value: Enables compact, low-noise isolated supply with <7 mA quiescent current - extends battery life and meets Class B conducted EMI limits. |
| Multi-Regulator Master/Slave System | Off-Line Boost Converter (≤50 W) |
Use Scenario: Coordinating three independent 12 V, 5 V, and 3.3 V regulators sharing a common 24 V input bus in industrial control modules. IC Role / Device Role / Timing Role: One MIC2172YN acts as master (SYNC resistor set to 135 kHz), others as slaves synchronized via capacitive coupling to VSW. Use Value: Prevents low-frequency beat interference (<20 kHz) between regulators - avoids audible noise and reduces output ripple filtering requirements. | Use Scenario: Stepping up rectified AC line (≈300 V DC) to 400 V DC bus in low-cost offline SMPS for LED drivers or small appliances. IC Role / Device Role / Timing Role: Predriver stage controlling external high-voltage MOSFET; MIC2172YN handles PWM generation and current sensing. Use Value: Leverages internal 1.25 A switch for auxiliary bias rails and provides robust cycle-by-cycle current protection - improves system reliability versus discrete controller solutions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PWM controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT1172CN8#PBF | No SYNC input; shutdown via VC pin voltage <0.15 V instead of dedicated EN/SYNC; 1.25 A switch, same 100 kHz freq. | Lacks master/slave synchronization; requires external transistor for enable control in new designs. | Select LT1172CN8#PBF only for legacy LT1172 socket reuse where sync is unnecessary and VC-based shutdown suffices. |
| MIC3172YN | Replaces SYNC with TTL-compatible EN pin; identical switch rating, oscillator, and pinout except Pin 4 function; <1 μA shutdown current. | Better suited for on/off-controlled single-rail systems; cannot synchronize multiple regulators. | Choose MIC3172YN when precise enable/disable sequencing is required and multi-regulator noise coordination is not needed. |
Compared with LT1172CN8#PBF and MIC3172YN, the MIC2172YN uniquely supports frequency synchronization for EMI-critical multi-rail systems, while retaining LT1172 socket compatibility and full 1.25 A switch capability - making it optimal for next-generation portable and industrial power designs requiring coordinated switching.
Availability
MIC2172YN is available at Aetrix Electronics and suitable for laptop power supplies, handheld instrumentation, multi-rail industrial controllers, and off-line boost converter designs requiring stable component supply and long-term manufacturability.
Supply support for MIC2172YN 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
Microchip Technology is a global semiconductor company specializing in microcontrollers, analog devices, and power management ICs, with emphasis on reliability, longevity, and industrial-grade performance.
The MIC2172YN belongs to Microchip's legacy high-voltage PWM controller product line, engineered for cost-sensitive, medium-power DC-DC conversion in portable and embedded systems where integration, thermal robustness, and topology flexibility are critical.
FAQ
What is the maximum output power achievable with the MIC2172YN in boost configuration?
The MIC2172YN supports up to 50 W output power in boost topology when used with an external power switch. With its internal 65 V / 1.25 A NPN switch, practical output is limited to ~15 W (e.g., 5 V → 12 V @ 0.14 A) due to conduction and switching losses. For higher power, the MIC2172YN serves as a predriver - the internal switch controls gate drive of an external MOSFET, enabling scalable designs. Thermal derating must be applied above 70°C ambient.
Can the MIC2172YN replace the LT1172 in existing designs without PCB changes?
Yes, the MIC2172YN is pin-compatible with the LT1172 in 8-pin DIP packages and shares identical pin functions except Pin 4 (SYNC vs. VC). In circuits without shutdown functionality, MIC2172YN operates directly as a drop-in replacement. Where LT1172 used VC pin for disable, a simple resistor divider or logic-level translator may be needed - but no PCB redesign is required. Full electrical validation per DS20006208A is recommended before production deployment of MIC2172YN.
How does the SYNC pin on the MIC2172YN function, and what signal levels are required?
The SYNC pin on the MIC2172YN accepts a capacitive-coupled external clock signal with amplitude ≥3.0 V peak-to-peak and frequency 105–135 kHz. Locking occurs on the falling edge of the input waveform. To increase oscillator frequency above 100 kHz, connect a resistor from SYNC to ground (e.g., 10 kΩ yields ~135 kHz). If unused, SYNC must float - never tie to GND or VIN. The MIC2172YN will not synchronize to signals below 100 kHz or with insufficient slew rate.
What is the purpose of the two power ground pins (PGND1 and PGND2) on the MIC2172YN?
PGND2 is mandatory for all topologies and connects to the main emitter path of the internal NPN switch. PGND1 is optional and parallels PGND2 with an identical 0.3 Ω current-sense resistor. Leaving PGND1 unconnected reduces the effective current limit to ~0.625 A (half of 1.25 A), enabling safe operation at lower output currents without redesign. Connecting PGND1 to PGND2 restores full 1.25 A capability - this dual-path architecture provides scalable current handling within the same MIC2172YN footprint.
Does the MIC2172YN support discontinuous conduction mode (DCM) in boost applications?
Yes, the MIC2172YN inherently supports discontinuous conduction mode (DCM) in boost converters, which simplifies loop compensation and improves light-load efficiency. DCM operation is achieved by selecting inductance such that the switch current falls to zero during the off-time - verified using Equation 5-6 from DS20006208A. The MIC2172YN's current-mode architecture ensures stable DCM operation without slope compensation, unlike voltage-mode controllers. Typical design examples (e.g., 5 V → 12 V) confirm reliable DCM across 0–100% load range.
MIC2172YN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Up, Step-Up/Step-Down
- Output Configuration:
- Positive or Negative, Isolation Capable
- Topology:
- Boost, Cuk, Flyback, Forward Converter
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- 65V (Switch)
- Current - Output:
- 1.25A (Switch)
- Frequency - Switching:
- 100kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
MIC2172YN FAQ
1.How can I place an order for MIC2172YN through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC2172YN 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 MIC2172YN reliable?
The price and inventory of MIC2172YN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC2172YN is usually 5 days.
3.What payment methods are accepted for MIC2172YN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC2172YN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC2172YN?
MIC2172YN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC2172YN 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 MIC2172YN?
For technical support, including MIC2172YN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC2172YN requirements.
6.How does Aetrix verify that MIC2172YN is sourced from the original manufacturer or authorized distributors?
All MIC2172YN 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 MIC2172YN meets industry standards.
7.What is the process for return or replacement of MIC2172YN?
All MIC2172YN units undergo pre-shipment inspection (PSI). If there is an issue with MIC2172YN, 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 MIC2172YN part is unused and in its original packaging.
Return procedure for MIC2172YN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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