My Inquiry
My Account
Analog Devices Inc. LT1575CN8-5#PBF
- Part No.:
- LT1575CN8-5#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
LT1575CN8-5#PBF.pdf
- Description:
- IC LNR REG CTRLR 1OUT 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:289
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT1575CN8-5#PBF from Analog Devices (formerly Linear Technology) is a fixed-output 5V, ultrafast transient response low dropout regulator controller IC designed to drive external N-channel MOSFETs in source-follower configuration for microprocessor core power supplies. It delivers ±1% output voltage accuracy over temperature, supports up to 5A load current, achieves <500ns transient response, and eliminates bulk electrolytic/tantalum output capacitors - confirmed in Pentium® and PowerPC™ supply applications.
For engineers reviewing the LT1575CN8-5#PBF datasheet, LT1575CN8-5#PBF pinout, LT1575CN8-5#PBF application, or LT1575CN8-5#PBF equivalent, this page provides verified circuit role (MOSFET gate driver for LDO controller), exact package (8-lead PDIP), validated pin functions, real-world transient performance data (0.2A–5A step), and two confirmed alternative parts with documented technical differences.
Technical Context
The LT1575CN8-5#PBF implements a high-gain error amplifier (84dB typical open-loop gain) with transconductance of 15 mS, driving an internal GATE output stage capable of sourcing/sinking 50mA peak for MOSFET gate slewing. Its feedback loop uses the OUT pin (not FB) as the inverting input, tied internally to a precision 1.21V reference, enabling fixed 5V regulation without external resistors.
Protection architecture includes a high-side current limit amplifier with 50mV threshold, a multifunction SHDN pin with 100mV hysteresis and programmable time-out latchoff, and start-up control that prevents false triggering during VIN ramp. The device operates from 0°C to 70°C ambient, with junction temperature limited to 100°C and θJA = 100°C/W in the N8 package.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5.000 V ±1.0% over 0°C to 70°C - enables direct replacement of 5V logic supply rails without resistor divider tuning. |
| Reference Accuracy | 1.210 V ±0.6% at 25°C, ±1.0% over full temp range - ensures tight output tolerance independent of external components. |
| Load Regulation | 1 mV typical - maintains stable 5V output across 0–5A load, critical for microprocessor core voltage stability. |
| Current Limit Threshold | 50 mV ±10 mV - sets precise overcurrent protection level via external sense resistor (e.g., 10 mΩ → 5A limit). |
| GATE Output Swing | VOH = VIN – 1.0 V, VOL = 2.5–3.0 V - provides sufficient gate drive headroom for N-MOSFETs with VGS(th) > 3V – VOUT. |
| Quiescent Current | 5–19 mA - scales with input voltage (5 mA at 12V typical), minimizing no-load power loss in always-on supplies. |
| Line Regulation | 0.01–0.03 %/V - rejects input ripple and variation, essential for clean 5V rail when VIN ranges from 10V–20V. |
Pinout & Package
LT1575CN8-5#PBF is housed in an 8-lead plastic DIP (N8) package with through-hole mounting and 100°C/W junction-to-ambient thermal resistance. Pin numbering follows standard dual-in-line orientation (Pin 1 = SHDN, top-left corner).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SHDN (1) | Multifunction shutdown input | Accepts 1.18–1.24V threshold with 100mV hysteresis; enables current-limit time-out latchoff, overvoltage protection, or thermal shutdown via external resistor divider. |
| VIN (2) | Main IC supply input | Powers internal circuitry and GATE driver; supports 12V nominal, 22V absolute max; minimum VIN = VOUT + VGS(th) + 1.6V. |
| GND (3) | Analog ground reference | Serves as negative sense terminal for 1.21V reference and return for feedback and compensation networks - must be star-connected for stability. |
| OUT (4) | Fixed-voltage feedback node | Inverting input of error amplifier for 5V version; connects directly to regulated output - no external divider required. |
| COMP (5) | Error amplifier high-Z gain node | External RC compensation point; transconductance = 15 mS; open-loop gain ≈ 84dB - determines loop bandwidth and phase margin. |
| GATE (6) | MOSFET gate driver output | Drives N-channel MOSFET gate with ≤5000pF capacitance; delivers 50mA peak for fast load transients; output impedance ≈ 2Ω. |
| INEG (7) | Negative current sense input | High-side current limit amplifier negative input; tie to IPOS to disable current limit, or ground for "sense-less" short-circuit protection. |
| IPOS (8) | Positive current sense input | High-side current limit amplifier positive input; connect to main input rail (e.g., 12V); also enables startup monitoring of VIN–VOUT differential. |
Key Features
| Feature | Design Value |
|---|---|
| Ultrafast transient response | Responds to 0.2A→5A load steps in <500ns - eliminates need for bulk tantalum/electrolytic output capacitors (only 24×1µF ceramics required). |
| FET RDS(ON)-defined dropout | Dropout voltage set solely by external MOSFET's on-resistance - enables sub-200mV dropout at 5A with suitable FET selection. |
| 1% output voltage tolerance | ±1% over 0°C to 70°C ambient - meets stringent microprocessor core supply specs without post-manufacturing trimming. |
| High-side sense current limit | 50mV threshold with programmable time-out latchoff - protects against sustained overloads while preserving MOSFET SOA. |
| Multifunction SHDN pin | Single pin supports current-limit timeout, overvoltage protection, thermal shutdown, or reset - reduces system component count and PCB area. |
Applications
| Pentium® Processor Core Supply | PowerPC™ I/O Supply |
|---|---|
|
Use Scenario: Powers Intel Pentium® processor core requiring 5V ±100mV with nanosecond-scale load transients during instruction execution. IC Role / Device Role / Timing Role: Controller IC driving external N-MOSFET to regulate 5V rail; provides gate drive, error amplification, and current limiting. Use Value: Enables use of only 24×1µF ceramic capacitors instead of bulky electrolytics - reduces BOM cost, board area, and insertion labor. |
Use Scenario: Supplies 5V I/O voltage to PowerPC™ processors where fast transient immunity prevents signal integrity degradation. IC Role / Device Role / Timing Role: Fixed-output LDO controller maintaining 5V under dynamic bus switching loads up to 5A. Use Value: Achieves <500ns transient recovery - prevents I/O voltage droop during address/data bus contention, ensuring reliable memory access. |
| GTL Bus Termination | Low-Voltage Logic Interface |
|
Use Scenario: Provides stable 5V termination voltage for GTL (Gunning Transceiver Logic) buses in high-speed backplanes. IC Role / Device Role / Timing Role: Precision 5V regulator with <1mV load regulation - maintains consistent GTL reference for impedance matching. Use Value: Eliminates voltage drift-induced timing skew across parallel GTL lines, supporting >100MHz bus operation. |
Use Scenario: Supplies 5V to mixed-signal logic families (e.g., TTL, CMOS) requiring clean, low-noise DC with minimal ripple. IC Role / Device Role / Timing Role: Low-dropout controller delivering 5V with 0.03%/V line regulation - rejects upstream supply noise. Use Value: Reduces logic switching jitter by suppressing supply-induced timing uncertainty - improves system-level timing margins. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC1702A-5#PBF | Fixed 5V output, 1.21V reference, but uses P-channel MOSFET topology (lower dropout at light loads); no high-side current sense; SHDN pin lacks latchoff timer. | Preferred for ultra-low-quiescent-current systems (<100µA) and where P-MOSFET layout simplifies routing; unsuitable for high-side current monitoring or programmable fault timeout. | Select LTC1702A-5#PBF only if P-MOSFET compatibility and sub-100µA IQ are mandatory; verify absence of high-side sensing does not compromise system protection requirements. |
| LT1585CT-5#PBF | Monolithic 5V LDO (not controller); integrated pass transistor; 3A max output; no external MOSFET drive; no SHDN latchoff or current limit amplifier. | Used in simpler, lower-current (≤3A) applications where board space is constrained and external FET drive is unnecessary. | Choose LT1585CT-5#PBF for cost-sensitive, low-complexity 5V supplies <3A; avoid when >3A, ultrafast transient response, or programmable current limiting is required. |
Compared with LTC1702A-5#PBF and LT1585CT-5#PBF, the LT1575CN8-5#PBF uniquely combines external N-MOSFET drive capability, high-side current sensing with programmable time-out latchoff, and <500ns transient response - making it the only option among the three qualified for demanding 5V microprocessor core supplies requiring >3A and ceramic-only output filtering.
Availability
LT1575CN8-5#PBF is available at Aetrix Electronics and suitable for Pentium® processor core supplies, PowerPC™ I/O rails, GTL bus termination, and low-voltage logic interfaces requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LT1575CN8-5#PBF 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, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving industrial, automotive, communications, and computing markets.
The LT1575 family was developed specifically for ultrafast transient-response microprocessor power supplies, addressing the need to eliminate bulk output capacitors while maintaining ±1% output accuracy and robust fault protection in high-current LDO controller designs.
FAQ
What is the primary function of the LT1575CN8-5#PBF in a power supply design?
The LT1575CN8-5#PBF is a fixed 5V low dropout regulator controller IC that drives an external N-channel MOSFET in source-follower configuration. It provides precision voltage regulation, ultrafast transient response (<500ns), high-side current limiting, and multifunction shutdown - all without requiring external feedback resistors due to its integrated 5V reference network.
Does the LT1575CN8-5#PBF require external resistors to set its 5V output?
No. The LT1575CN8-5#PBF is a fixed-output variant with an internal precision resistor divider network referenced to the 1.21V bandgap. The OUT pin (Pin 4) serves as the inverting input of the error amplifier and connects directly to the regulated 5V output - no external resistors are needed for voltage setting.
What is the maximum load current supported by the LT1575CN8-5#PBF?
The LT1575CN8-5#PBF itself does not supply load current - it controls an external N-channel MOSFET. Load current capability depends on the selected MOSFET's RDS(ON), thermal design, and PCB layout. The datasheet validates operation up to 5A with appropriate FETs (e.g., IRFZ24) and 24×1µF ceramic output capacitance.
How does the SHDN pin on the LT1575CN8-5#PBF provide overvoltage protection?
The SHDN pin on the LT1575CN8-5#PBF serves as the positive input to a comparator referenced to the internal 1.21V reference. When driven above 1.24V (typical threshold), it latches the GATE output low, disabling the external MOSFET. An external resistor divider from the output rail to SHDN allows precise overvoltage trip points - e.g., 5.5V output triggers shutdown at ~1.22V on SHDN.
Can the LT1575CN8-5#PBF operate without a current sense resistor?
Yes. To disable current limiting, tie INEG (Pin 7) directly to IPOS (Pin 8). Alternatively, grounding INEG activates "sense-less" short-circuit protection: the IC monitors GATE saturation and triggers the SHDN timer if the MOSFET drives fully to VIN, providing basic fault coverage without external components.
LT1575CN8-5#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Active
- Type:
- Positive Fixed
- Number of Outputs:
- 1
- Current - Supply:
- 12mA
- Voltage - Input:
- 10V ~ 20V
- Operating Temperature:
- 0°C ~ 70°C
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
LT1575CN8-5#PBF FAQ
1.How can I place an order for LT1575CN8-5#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1575CN8-5#PBF 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 LT1575CN8-5#PBF reliable?
The price and inventory of LT1575CN8-5#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1575CN8-5#PBF is usually 5 days.
3.What payment methods are accepted for LT1575CN8-5#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1575CN8-5#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1575CN8-5#PBF?
LT1575CN8-5#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1575CN8-5#PBF 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 LT1575CN8-5#PBF?
For technical support, including LT1575CN8-5#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1575CN8-5#PBF requirements.
6.How does Aetrix verify that LT1575CN8-5#PBF is sourced from the original manufacturer or authorized distributors?
All LT1575CN8-5#PBF 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 LT1575CN8-5#PBF meets industry standards.
7.What is the process for return or replacement of LT1575CN8-5#PBF?
All LT1575CN8-5#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1575CN8-5#PBF, 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 LT1575CN8-5#PBF part is unused and in its original packaging.
Return procedure for LT1575CN8-5#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT1575CN8-5#PBF Tags
-
LT1575CS8#PBF
Analog Devices Inc.
-
RT9008GE
Richtek USA Inc.
-
S-816A40AMC-BAPT2U
ABLIC Inc.
-
MIC5159YM6-TR
Microchip Technology
-
MIC5156YM
Microchip Technology
-
MIC5156-3.3YM
Microchip Technology
-
MIC5158YM-TR
Microchip Technology
-
MAX8564AEUB+
Analog Devices Inc./Maxim Integrated
-
LT1573CS8#PBF
Analog Devices Inc.
-
UC2834DW
Texas Instruments
-
RT9194GE
Richtek USA Inc.
-
S-816A33AMC-BAIT2U
ABLIC Inc.
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
