My Inquiry
My Account
Analog Devices Inc. LT1173CN8-5#PBF
- Part No.:
- LT1173CN8-5#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
LT1173CN8-5#PBF.pdf
- Description:
- IC REG BUCK BOOST 5V 1.5A 8PDIP
- Quantity:
- Payment:
- Shipping:
Inventory:2,805
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT1173CN8-5#PBF from Analog Devices (formerly Linear Technology) is a fixed-output 5V micropower DC/DC converter IC in step-up, step-down, or inverting configurations. It operates from 2.0V to 30V input, delivers up to 200mA at 5V from 12V input (step-down), consumes only 135µA quiescent current in boost mode, integrates a 1A internal power switch, and uses an 8-pin MiniDIP package for compact board space. It is used in battery-powered flash memory VPP generation and portable instrument power rails.
For engineers reviewing the LT1173CN8-5#PBF datasheet, LT1173CN8-5#PBF pinout, LT1173CN8-5#PBF application, or LT1173CN8-5#PBF equivalent, key selection criteria include its fixed 5V output tolerance (±5%), programmable current limit via ILIM pin, on-chip low-battery comparator, 23kHz oscillator frequency, and compatibility with Schottky catch diodes like 1N5818 in boost topology.
Technical Context
The LT1173CN8-5#PBF implements a gated-oscillator architecture where switching occurs only when feedback voltage drops below the 1.245V internal reference, enabling ultra-low 135µA quiescent current in boost mode. Its adaptive base drive ensures NPN power switch saturation without overdrive, improving efficiency across input ranges.
It supports three topologies: step-up (VIN = 2.0–12.6V), step-down (VIN = up to 30V), and inverting. Fixed 5V output is set by internal resistor divider (pin 8 = FB/SENSE connected to VOUT); no external feedback resistors are required. The auxiliary gain block (SET/AO pins) functions as a low-battery detector or error amplifier with 400–1000 V/V gain.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5.00V ±5% (guaranteed over temperature and line/load) |
| Input Voltage Range | 2.0V–12.6V (step-up), up to 30V (step-down); enables single-supply operation from coin cells or 12V rails |
| Quiescent Current | 135µA typical in boost mode (no load); critical for >1-year battery life in low-duty-cycle devices |
| Oscillator Frequency | 18–30kHz (typ. 23kHz); sets inductor size and EMI profile - lower than modern converters but optimized for efficiency at light loads |
| Switch Current Limit | Programmable up to 1.5A peak via ILIM-to-VIN resistor; prevents inductor saturation and switch overstress during input transients |
| Operating Temperature | 0°C to +70°C; suitable for commercial-grade portable and industrial embedded applications |
| Package | 8-pin plastic DIP (N8); through-hole mounting for prototyping and high-reliability manual assembly |
Pinout & Package
LT1173CN8-5#PBF uses an 8-lead plastic DIP (N8) package with 0.3-inch width and standard through-hole footprint. Pin 1 is ILIM, pin 2 is VIN, pin 3 is SW1 (collector of internal NPN switch), pin 4 is SW2 (emitter), pin 5 is GND, pin 6 is AO (auxiliary gain block open-collector output), pin 7 is SET (gain block non-inverting input), and pin 8 is FB/SENSE (feedback input tied internally to 5V divider).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| ILIM (Pin 1) | Current limit programming node | Resistor from ILIM to VIN sets peak switch current; 220Ω yields ~400mA limit - protects against inductor saturation during input surges |
| VIN (Pin 2) | Main power input | Accepts 2.0–30V; supplies internal bias, oscillator, and switch driver - no external LDO needed |
| SW1 (Pin 3) | Internal NPN collector | In step-up: connects to inductor/diode; in step-down: connects to VIN - defines switching node polarity and topology |
| SW2 (Pin 4) | Internal NPN emitter | In step-up: grounded; in step-down: drives inductor - must not swing below –0.5V to avoid latch-up |
| GND (Pin 5) | Power and signal reference | Common return for all internal circuits; requires low-impedance PCB plane for stable regulation |
| AO (Pin 6) | Gain block output | Open-collector NPN; sinks up to 100µA - drives microcontroller interrupt or LED indicator for low-battery detection |
| SET (Pin 7) | Gain block non-inverting input | Connects to resistor divider from VIN; sets comparator trip point (e.g., 3.0V battery low threshold) |
| FB/SENSE (Pin 8) | Feedback input | Internally connected to 5V divider; must be wired directly to VOUT - no external resistors required for fixed output |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 5V output with internal resistor network | Eliminates external feedback components - reduces BOM count and layout complexity for cost-sensitive designs |
| Programmable peak switch current limit | Enables robust operation across wide input ranges (e.g., 3V–12V batteries) without risking switch failure or inductor saturation |
| On-chip low-battery comparator | Uses internal 1.245V reference and SET pin to detect falling VIN - provides system-level battery monitoring without external comparators |
| Gated-oscillator architecture | Switches only when output droops - achieves 135µA quiescent current in boost mode, extending shelf life in standby applications |
| Three-mode topology support | Single IC supports boost, buck, and inverting configurations - simplifies inventory and design reuse across multiple power rail requirements |
Applications
| Flash Memory VPP Generation | Portable Instrument Power Supply |
|---|---|
Use Scenario: Generating +12V programming voltage (VPP) for NOR/NAND flash memory from a 3V or 5V battery source in handheld data loggers. IC Role / Device Role / Timing Role: Step-up DC/DC converter with fixed 5V output variant repurposed via external feedback to deliver regulated 12V using LT1173 adjustable configuration - though LT1173CN8-5#PBF is fixed 5V, it serves as baseline for family used in VPP designs. Use Value: Enables in-system flash reprogramming without external high-voltage generators - reduces component count and PCB area versus discrete charge-pump solutions. | Use Scenario: Providing stable 5V rail for microcontroller, ADC, and LCD in battery-powered multimeters or environmental sensors operating 24/7 on AA cells. IC Role / Device Role / Timing Role: Primary 5V power regulator in step-down mode (12V input from wall adapter) or step-up mode (3V input from batteries), leveraging low 135µA quiescent current to maximize runtime. Use Value: Delivers 200mA at 5V from 12V input with 81% efficiency - sustains active measurement cycles while preserving battery capacity during long idle periods. |
| Laptop/Palmtop Peripheral Cards | Cellular Telephone Backup Supply |
Use Scenario: Powering PCMCIA or CompactFlash peripherals requiring isolated 5V from host 3.3V or 5V logic rails in legacy laptop expansion slots. IC Role / Device Role / Timing Role: Step-up converter generating clean 5V from 3.3V supply; uses internal 1A switch and Schottky diode (1N5818) for minimal dropout and ripple. Use Value: Meets PCMCIA spec for +5V tolerance (±5%) and transient response - avoids brownouts during card insertion or burst data transfers. | Use Scenario: Maintaining real-time clock (RTC) and SRAM backup during main battery removal or deep discharge in GSM handsets. IC Role / Device Role / Timing Role: Low-quiescent-current step-down regulator converting 4.2V Li-ion to 3.3V or 5V backup rail; leverages ILIM pin to clamp inrush during capacitor charging. Use Value: Draws only 135µA when idle - extends RTC hold-up time beyond 72 hours on a 10µF backup capacitor charged from depleted main battery. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar DC/DC converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT1173CS8-5#PBF | Same electrical specs, but in 8-lead SOIC (S8) surface-mount package - 150°C/W θJA vs. 130°C/W for DIP | Better thermal performance in dense layouts; requires reflow soldering - unsuitable for hand-soldered prototypes or through-hole-only assemblies | Select LT1173CS8-5#PBF for volume production with SMT lines; retain LT1173CN8-5#PBF for breadboarding, repair, or mixed-technology boards. |
| LT1073CN8-5#PBF | Lower minimum input voltage (1.0V vs. 2.0V); 72kHz oscillator; higher quiescent current (250µA); same 5V fixed output and pinout | Enables operation from single NiMH or alkaline cell (<1.5V); faster switching allows smaller inductors but increases EMI sensitivity | Choose LT1073CN8-5#PBF when input may drop below 2.0V; use LT1173CN8-5#PBF where ultra-low IQ and proven 2–12V boost stability are prioritized. |
Compared with LT1173CS8-5#PBF, the LT1173CN8-5#PBF offers superior thermal resistance for low-power prototyping but lacks SMT scalability; versus LT1073CN8-5#PBF, it trades wider input range and lower IQ for inability to start below 2.0V - making it optimal for 3V+ battery or adapter-fed systems demanding longevity.
Availability
LT1173CN8-5#PBF is available at Aetrix Electronics and suitable for portable instrumentation, flash memory programming, and cellular backup power supplies requiring stable component supply, long-lifecycle availability, and through-hole manufacturability.
Supply support for LT1173CN8-5#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. (ADI) acquired Linear Technology in 2017 and maintains full technical and supply chain support for legacy Linear products including the LT1173 family.
The LT1173 product line was designed for ultra-low-power DC/DC conversion in battery-critical applications such as portable medical devices, memory programmers, and handheld test equipment - emphasizing micropower operation, topology flexibility, and integrated protection features.
FAQ
What is the output voltage tolerance of the LT1173CN8-5#PBF under full load and temperature?
The LT1173CN8-5#PBF guarantees a 5.00V output within ±5% (4.75V to 5.25V) across 0°C to +70°C operating temperature and full load conditions, as specified in the Electrical Characteristics table under VOUT for LT1173-5. This tolerance is maintained by internal precision resistor trimming and the 1.245V reference.
Can the LT1173CN8-5#PBF operate in step-down mode with a 24V input?
Yes, the LT1173CN8-5#PBF supports step-down operation up to 30V input. With a 24V input, it can deliver 5V at up to 200mA while maintaining regulation, provided external components (inductor, diode, capacitor) are selected per the datasheet guidelines - e.g., 220µH inductor with 100Ω ILIM resistor for current limiting.
Does the LT1173CN8-5#PBF require external feedback resistors to set its 5V output?
No, the LT1173CN8-5#PBF does not require external feedback resistors. Its 5V output is set by an internal resistor divider connected to the FB/SENSE pin (Pin 8), which must be wired directly to the output. This eliminates component count and layout variability versus the adjustable LT1173 version.
What is the maximum switch current rating for the LT1173CN8-5#PBF, and how is it controlled?
LT1173CN8-5#PBF has a maximum switch current rating of 1.5A peak. This is controlled via the ILIM pin (Pin 1): connecting a resistor between ILIM and VIN programs the current limit - for example, a 220Ω resistor limits peak current to ~400mA, preventing inductor saturation and thermal overload during input transients.
Is the LT1173CN8-5#PBF RoHS compliant and lead-free?
Yes, the LT1173CN8-5#PBF is RoHS compliant and lead-free. The "#PBF" suffix explicitly denotes Pb-Free (lead-free) packaging per Analog Devices' product marking convention, and it meets JEDEC J-STD-020 moisture sensitivity level 1 requirements for through-hole assembly.
LT1173CN8-5#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Up, Step-Down
- Output Configuration:
- Positive or Negative
- Topology:
- Buck, Boost
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2V
- Voltage - Input (Max):
- 30V
- Voltage - Output (Min/Fixed):
- 5V
- Voltage - Output (Max):
- -
- Current - Output:
- 1.5A (Switch)
- Frequency - Switching:
- 23kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
LT1173CN8-5#PBF FAQ
1.How can I place an order for LT1173CN8-5#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1173CN8-5#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 LT1173CN8-5#PBF reliable?
The price and inventory of LT1173CN8-5#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1173CN8-5#PBF is usually 5 days.
3.What payment methods are accepted for LT1173CN8-5#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1173CN8-5#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1173CN8-5#PBF?
LT1173CN8-5#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1173CN8-5#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 LT1173CN8-5#PBF?
For technical support, including LT1173CN8-5#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1173CN8-5#PBF requirements.
6.How does Aetrix verify that LT1173CN8-5#PBF is sourced from the original manufacturer or authorized distributors?
All LT1173CN8-5#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 LT1173CN8-5#PBF meets industry standards.
7.What is the process for return or replacement of LT1173CN8-5#PBF?
All LT1173CN8-5#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1173CN8-5#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 LT1173CN8-5#PBF part is unused and in its original packaging.
Return procedure for LT1173CN8-5#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT1173CN8-5#PBF Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
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…
