My Inquiry
My Account
Analog Devices Inc. LT1317BCS8#PBF
- Part No.:
- LT1317BCS8#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LT1317BCS8#PBF.pdf
- Description:
- IC REG BST SEPIC ADJ 710MA 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:159
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT1317BCS8#PBF from Analog Devices (formerly Linear Technology) is a micropower, fixed-frequency 600kHz step-up DC/DC converter optimized for battery-powered systems requiring stable 3.3V or 5V output from low-input sources (1.5V–12V). It features a 500mA internal NPN switch with 300mV VCE(SAT), 1.24V feedback reference, integrated low-battery detector (200mV threshold), and continuous switching operation-no Burst Mode-to eliminate low-frequency output ripple. It is used in glucose meters, portable medical instrumentation, and single-cell Li-ion to 5V power supplies.
For engineers reviewing the LT1317BCS8#PBF datasheet, LT1317BCS8#PBF pinout, LT1317BCS8#PBF application, or LT1317BCS8#PBF equivalent, key selection criteria include its fixed 600kHz PWM architecture, absence of light-load Burst Mode (vs. LT1317), 300mV switch saturation voltage, 1.24V FB reference tolerance (±2%), and SO-8 package compatibility with LT1307B-based designs.
Technical Context
The LT1317BCS8#PBF implements current-mode PWM control with a 600kHz oscillator and ramp compensation to prevent subharmonic oscillation above 50% duty cycle. Its error amplifier (70–240 µmhos transconductance, 700 V/V gain) drives an internal NPN switch via a 0.08Ω driver stage, enabling precise output regulation via external resistor divider on the FB pin.
Unlike the LT1317, the LT1317B variant disables Burst Mode by lowering the A1 comparator bias point, ensuring continuous switching at all loads-including 300µA-and eliminating low-frequency ripple at the expense of light-load efficiency. The low-battery detector (LBI/LBO) remains fully active during shutdown, with 200mV ±10mV threshold and open-collector LBO output capable of sinking 10µA.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | 600 kHz (fixed, ±120 kHz over temp/voltage; enables compact magnetics and predictable EMI filtering) |
| Feedback Voltage | 1.24 V (±2% over temp; sets output via R1/R2 divider: VOUT = 1.24 × (1 + R1/R2)) |
| Input Voltage Range | 1.5 V to 12 V (supports 1–8 alkaline/NiMH cells or single Li-ion down to 2.7 V with headroom) |
| Switch VCE(SAT) | 300 mV at 500 mA (low conduction loss; enables >80% efficiency at 100 mA with 2V input → 3.3V) |
| Quiescent Current | 7.5 mA (switching, VSHDN = 2 V; higher than LT1317 but ensures ripple-free light-load operation) |
| Low-Battery Threshold | 200 mV ±10 mV (stable reference for LBI pin; remains active in shutdown for system-level battery monitoring) |
| Max Duty Cycle | 85% (enables high step-up ratios; e.g., 1.5V → 5V requires ~70% duty cycle) |
Pinout & Package
LT1317BCS8#PBF is housed in an 8-lead plastic SO (Small Outline) package (S8), 0.150" wide, with standard SO-8 footprint (JEDEC MS-012), θJA = 120°C/W, and lead finish matte tin.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VC (Pin 1) | Compensation node for error amplifier | Connect external RC network (e.g., 33kΩ + 3.3nF) to ground; critical for loop stability with ceramic output caps |
| FB (Pin 2) | Feedback input | Monitors divided output voltage; 1.24V reference sets regulation point; bias current <60 nA minimizes divider error |
| SHDN (Pin 3) | Enable/disable control | Logic-compatible input: ≥1.4V enables, ≤0.4V shuts down (only LBI/LBO remain active) |
| GND (Pin 4) | Power and signal ground | Must connect directly to local ground plane; shared return for switch, FB, and VC paths |
| SW (Pin 5) | Switch collector node | Drives external inductor/diode; high di/dt path-minimize trace area to reduce EMI |
| VIN (Pin 6) | Main supply input | Accepts 1.5–12V; requires local 10µF bypass capacitor placed <5mm from pin |
| LBI (Pin 7) | Low-battery detector input | High-impedance PNP input referenced to 200mV; voltage range 0–0.7V; bias current flows out (≤40 nA) |
| LBO (Pin 8) | Low-battery detector output | Open-collector NPN output; sinks 10µA when LBI < 200mV; requires external pull-up (e.g., 1MΩ to VOUT) |
Key Features
| Feature | Design Value |
|---|---|
| Continuous 600kHz PWM operation | Eliminates low-frequency output ripple at light loads-critical for noise-sensitive analog/medical circuits |
| Integrated 500mA NPN switch with 300mV VCE(SAT) | Reduces external component count and conduction losses; supports up to 200mA output at high efficiency |
| Active low-battery detector in shutdown mode | Enables system-level battery monitoring without waking main converter-extends standby time in portable diagnostics |
| 1.24V ±2% feedback reference | Ensures accurate output regulation across temperature; simplifies resistor selection for 3.3V/5V/8.2V outputs |
| SO-8 package with pin-for-pin compatibility to LT1307B | Allows drop-in replacement in existing layouts; supports reflow soldering and automated assembly |
Applications
| Glucose Meters | Portable Diagnostic Instruments |
|---|---|
Use Scenario: Battery-powered handheld device measuring blood glucose concentration using electrochemical sensor strips. IC Role / Device Role / Timing Role: Step-up converter generating stable 3.3V rail from single 1.5V alkaline cell for microcontroller, ADC, and sensor bias. Use Value: Continuous 600kHz operation prevents low-frequency ripple from coupling into sensitive analog front-end, preserving measurement accuracy. | Use Scenario: Field-deployable diagnostic tool performing rapid immunoassay or PCR readout with LCD display and wireless reporting. IC Role / Device Role / Timing Role: Primary DC/DC converter delivering regulated 5V from 3.7V Li-ion cell to power MCU, display backlight, and BLE radio. Use Value: Integrated low-battery detector (active in shutdown) enables precise end-of-life warning while minimizing quiescent drain-extending usable battery life by >15%. |
| Single-Cell Li-ion to 5V Power Supply | Low-Noise Varactor Bias Supply |
Use Scenario: Compact consumer electronics (e.g., Bluetooth earbuds, smart pens) requiring 5V USB-compatible output from 2.7–4.2V Li-ion cell. IC Role / Device Role / Timing Role: Fixed-frequency boost converter with external 10µH inductor and Schottky diode, configured for 5V/125mA output. Use Value: 300mV switch VCE(SAT) and 85% max duty cycle enable >78% efficiency across full input range-maximizing runtime. | Use Scenario: RF front-end module requiring ultra-low-noise negative bias (–4V) and positive bias (4.1V) for varactor tuning diodes in cellular transceivers. IC Role / Device Role / Timing Role: Dual-output SEPIC/boost controller generating isolated ±4V rails from 1.5–10V input using coupled inductors and dual diodes. Use Value: Absence of Burst Mode eliminates switching-frequency sidebands near carrier-reducing phase noise in VCO tuning path. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-up DC/DC converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT1317CS8#PBF | Includes Burst Mode at light loads; 100µA quiescent current vs. 7.5mA; same pinout and package | Preferred where >100-hour standby is required and low-frequency ripple is acceptable (e.g., non-analog consumer devices) | Select LT1317BCS8#PBF when ripple-sensitive loads demand continuous switching; choose LT1317CS8#PBF only if light-load efficiency is primary concern. |
| LT1307BCS8#PBF | Lower 1.5V min input (vs. 1.5V), identical 600kHz freq, same SO-8 pinout, but no LBI/LBO pins or low-battery detection | Suitable for cost-sensitive, non-battery-monitoring applications (e.g., LED drivers); lacks system-level battery management capability | Use LT1317BCS8#PBF when integrated low-battery monitoring is required; LT1307BCS8#PBF is viable only if LBI/LBO functionality is omitted from design. |
Compared with LT1317CS8#PBF, the LT1317BCS8#PBF trades 7.4mA higher operating current for ripple-free regulation-critical in medical analog stages-while matching output accuracy and thermal performance. Against LT1307BCS8#PBF, it adds essential battery supervision at no PCB layout change, enabling smarter power management in portable diagnostics.
Availability
LT1317BCS8#PBF is available at Aetrix Electronics and suitable for glucose meters, portable diagnostic instruments, single-cell Li-ion to 5V power supplies, and low-noise RF bias supplies requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LT1317BCS8#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 acquired Linear Technology in 2017 and maintains full product support, datasheet archives, and application engineering for legacy Linear parts including the LT1317 series.
The LT1317 family was designed specifically for micropower, wide-input-range boost conversion in space-constrained, battery-operated medical and portable instrumentation-emphasizing low-noise operation, integrated supervision, and robustness across temperature and load extremes.
FAQ
What is the minimum input voltage supported by the LT1317BCS8#PBF?
The LT1317BCS8#PBF supports a minimum input voltage of 1.5V, enabling operation from a single alkaline or NiMH cell. This is confirmed in the Electrical Characteristics table under "Input Voltage Range" (1.5V to 12V, Commercial Grade). At 1.5V input, the device can still deliver regulated 3.3V output with appropriate external components (e.g., 10µH inductor, Schottky diode), though efficiency drops below 70% at full load due to duty cycle constraints.
Does the LT1317BCS8#PBF enter Burst Mode operation at light loads?
No, the LT1317BCS8#PBF does not enter Burst Mode operation at light loads. Unlike the LT1317 variant, the "B" suffix denotes continuous fixed-frequency 600kHz switching across the entire 300µA–200mA load range. This eliminates low-frequency output ripple-a key differentiator explicitly stated in the Features section and illustrated in Figure 2 of the datasheet. The trade-off is higher light-load quiescent current (7.5mA vs. 100µA for LT1317).
What is the function of the LBI and LBO pins on the LT1317BCS8#PBF?
The LBI (Low-Battery Input) pin accepts a scaled battery voltage and compares it to an internal 200mV reference; the LBO (Low-Battery Output) pin is an open-collector output that pulls low when LBI falls below 200mV. Critically, this detector remains fully active-even when the main converter is in shutdown (SHDN = 0V)-enabling system-level battery monitoring without waking the power stage. LBO requires an external pull-up resistor (e.g., 1MΩ to VOUT) to generate a logic-level signal.
Can the LT1317BCS8#PBF be used with ceramic output capacitors?
Yes, the LT1317BCS8#PBF supports ceramic output capacitors, but compensation must be adjusted. The standard RC network (33kΩ + 3.3nF) is optimized for tantalum caps; for ceramics, Figure 4 in the datasheet recommends reducing RC to 20kΩ + 1500pF and adding a 100pF capacitor from VC to GND to ensure stability and optimal transient response. Failure to adjust compensation may cause ringing or oscillation due to the ceramic cap's ultra-low ESR.
What is the maximum output current achievable with the LT1317BCS8#PBF?
The LT1317BCS8#PBF is rated for up to 200mA output current under typical conditions (e.g., 2V input → 3.3V output), as verified in the "2-Cell to 3.3V Converter Efficiency" plot (Figure TA01) and Typical Application circuits. Peak switch current is limited to ≥660mA (typical), but practical output depends on input voltage, inductor DCR, diode forward drop, and thermal management. At 1.5V input, maximum sustainable output drops to ~125mA due to duty cycle and switch loss limitations.
LT1317BCS8#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Up, Step-Up/Step-Down
- Output Configuration:
- Positive
- Topology:
- Boost, SEPIC
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 1.5V
- Voltage - Input (Max):
- 12V
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- 30V (Switch)
- Current - Output:
- 710mA (Switch)
- Frequency - Switching:
- 620kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SO
LT1317BCS8#PBF FAQ
1.How can I place an order for LT1317BCS8#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1317BCS8#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 LT1317BCS8#PBF reliable?
The price and inventory of LT1317BCS8#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1317BCS8#PBF is usually 5 days.
3.What payment methods are accepted for LT1317BCS8#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1317BCS8#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1317BCS8#PBF?
LT1317BCS8#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1317BCS8#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 LT1317BCS8#PBF?
For technical support, including LT1317BCS8#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1317BCS8#PBF requirements.
6.How does Aetrix verify that LT1317BCS8#PBF is sourced from the original manufacturer or authorized distributors?
All LT1317BCS8#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 LT1317BCS8#PBF meets industry standards.
7.What is the process for return or replacement of LT1317BCS8#PBF?
All LT1317BCS8#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1317BCS8#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 LT1317BCS8#PBF part is unused and in its original packaging.
Return procedure for LT1317BCS8#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT1317BCS8#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…
