My Inquiry
My Account
Analog Devices Inc. LT1950EGN#TRPBF
- Part No.:
- LT1950EGN#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 16-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
LT1950EGN#TRPBF.pdf
- Description:
- IC REG CTRLR MULT TOP 16SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,593
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT1950EGN#TRPBF from Analog Devices (formerly Linear Technology) is a wide-input-range, current-mode PWM controller for forward, flyback, boost, and SEPIC DC/DC converters, driving external N-channel MOSFETs. It features programmable 100–500 kHz switching frequency, 60 ns current sense delay, ±2% 1.23 V internal reference, 2.5 V auxiliary reference output, and integrated auxiliary boost converter enabling 10 V gate drive from as low as 3 V input-used in telecom power supplies and isolated 36–72 V to 26 V/5 A forward converters.
For engineers reviewing the LT1950EGN#TRPBF datasheet, LT1950EGN#TRPBF pinout, LT1950EGN#TRPBF application, or LT1950EGN#TRPBF equivalent, key selection considerations include volt-second clamp programming via VSEC, slope compensation adjustability, leading edge blanking control, and synchronized operation up to 1.5× fOSC-all critical for stable high-power isolated converter design under wide VIN and variable load conditions.
Technical Context
The LT1950EGN#TRPBF implements true current-mode control with externally adjustable slope compensation (via SLOPE pin to VREF), programmable leading edge blanking (BLANK pin to ground), and a fast 60 ns current sense path. Its error amplifier is a full op-amp with 85 dB open-loop gain and 3 MHz unity-gain bandwidth, supporting flexible loop compensation.
It integrates an auxiliary boost switcher (BOOST pin) with fixed 0.5 µs off-time and 125 mA current limit, generating regulated 10–11 V at VIN2 for robust gate drive-even when main VIN drops to 3 V. The maximum duty cycle is programmable via VSEC (105/VSEC %, 1.4–2.8 V range), enabling precise volt-second clamping essential for forward converter reset safety.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3 V to 25 V - supports battery-backed, telecom, and automotive inputs without pre-regulation |
| Switching Frequency | 100 kHz to 500 kHz - set by single ROSC resistor; enables optimization of magnetics size vs. efficiency |
| Current Sense Delay | 60 ns - ensures accurate peak-current sampling even with fast-switching MOSFETs |
| FB Reference Voltage | 1.23 V ±2% - sets output voltage accuracy via external resistor divider; stable over –40°C to 125°C |
| VREF Output | 2.500 V ±0.075 V, 2.5 mA capable - powers external circuitry (e.g., bias networks, sensing ICs) with low drift |
| Shutdown Threshold | 1.32 V ±0.06 V with programmable hysteresis - enables precise undervoltage lockout (UVLO) for battery or high-impedance sources |
| GATE Drive Capability | 10 V min at VIN2 ≥ 8 V; clamped to 13 V max - ensures full enhancement of standard-level N-MOSFETs |
| Max Duty Cycle Clamp | (105/VSEC)% for VSEC = 1.4–2.8 V - provides hardware-enforced volt-second limit for forward transformer reset |
Pinout & Package
LT1950EGN#TRPBF is housed in a 16-lead narrow plastic SSOP (GN) package with 0.65 mm lead pitch and exposed thermal pad (pin 8 = GND). Thermal resistance θJA = 110°C/W; θJC = 30°C/W (pin 8).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| COMP (1) | Error amplifier output | Drives feedback loop compensation network; controls ISENSE threshold; typical operating range 1–2.5 V |
| FB (2) | Inverting input of error amp | Compares output voltage divider to 1.23 V reference; sets regulated output voltage |
| ROSC (3) | Oscillator timing node | Resistor-to-ground sets fOSC; nominal voltage 1 V; supports 100–500 kHz range |
| SYNC (4) | External clock input | Accepts logic-level signal (10–90% duty); synchronizes to external clock up to 1.5× fOSC |
| SLOPE (5) | Slope compensation adjust | Open = default compensation; resistor to VREF increases ramp amplitude to prevent subharmonic oscillation |
| VREF (6) | 2.5 V reference output | Stable, bypassed (0.1 µF) output sourcing up to 2.5 mA for external use |
| SHDN (7) | Shutdown enable | 1.32 V threshold with programmable hysteresis; pulls device into 5 µA shutdown state |
| GND (8) | Analog ground | Reference for FB, ROSC, VREF; must be star-connected to minimize noise coupling |
| BLANK (9) | Leading edge blanking control | Ground = 110 ns blanking; resistor to ground extends up to 290 ns to suppress turn-on noise |
| ISENSE (10) | Current sense input | Compares MOSFET source voltage to COMP-derived threshold; 100 mV max clamp |
| VIN2 (11) | Gate driver supply input | Must exceed 8 V to enable GATE; can be supplied externally or via BOOST-generated 10–11 V |
| GATE (12) | MOSFET gate driver output | High-current (±200 mA) push-pull output; actively clamped to ≤13 V |
| PGND (13) | Power ground | Return path for GATE driver current; separate from analog GND to reduce noise |
| BOOST (14) | Internal boost switch collector | Drives external inductor/diode/capacitor to generate VIN2 from low VIN (≥3 V) |
| VIN (15) | Main supply input | 3–25 V input; powers internal circuitry; UVLO at 2.6 V; bypass with ceramic capacitor |
| VSEC (16) | Volt-second clamp control | Programs max duty cycle as (105/VSEC)%; critical for forward converter core reset protection |
Key Features
| Feature | Design Value |
|---|---|
| Integrated auxiliary boost converter | Generates 10–11 V at VIN2 from VIN ≥ 3 V, enabling full gate drive for standard N-MOSFETs without external bias supply |
| Programmable slope compensation | Adjustable via external resistor on SLOPE pin-eliminates subharmonic oscillation across all inductor values and frequencies |
| 60 ns current sense delay | Minimizes propagation delay between sense event and GATE turn-off-critical for stability at high fOSC and low duty cycles |
| Volt-second clamp via VSEC | Hardware-based (105/VSEC)% max duty cycle limit prevents transformer saturation in forward topologies |
| True op-amp error amplifier | 85 dB gain, 3 MHz GBW, and rail-to-rail COMP output enable wide-ranging compensation networks and fast transient response |
| Synchronizable oscillator | SYNC pin accepts external clock up to 500 kHz (1.5× nominal fOSC)-enables EMI reduction and multi-phase interleaving |
Applications
| Telecom Power Supplies | Automotive Power Supplies |
|---|---|
Use Scenario: 36–72 V DC input converted to isolated 26 V/5 A for base station RF amplifiers. IC Role / Device Role / Timing Role: Primary-side PWM controller implementing forward topology with volt-second clamp and synchronous rectification support. Use Value: VSEC-programmed duty cycle clamp ensures safe transformer reset; BOOST-enabled 10 V gate drive maintains low RDS(on) across wide input range. |
Use Scenario: 12 V battery input stepped up to 24 V for ADAS camera modules requiring stable, low-noise supply. IC Role / Device Role / Timing Role: Boost controller with programmable UVLO (via SHDN) and temperature-stable 1.23 V reference for precision output regulation. Use Value: ±2% FB reference and 60 ns current sense delay ensure tight output tolerance and fast load transient recovery under engine cranking conditions. |
| Isolated DC/DC Converters | Portable Electronic Equipment |
Use Scenario: Medical-grade isolated 48 V to 5 V/10 A flyback supply with reinforced insulation and low leakage. IC Role / Device Role / Timing Role: Current-mode flyback controller with leading edge blanking (BLANK pin) and slope compensation for stable operation at >50% duty cycle. Use Value: Adjustable blanking (up to 290 ns) rejects transformer leakage spikes; 2.5 V VREF powers optocoupler bias, improving regulation accuracy. |
Use Scenario: USB-C PD adapter with variable 5–20 V output using SEPIC architecture for wide-input compatibility. IC Role / Device Role / Timing Role: SEPIC controller with ROSC-programmable frequency (200 kHz typical) and SYNC capability for EMI spread-spectrum tuning. Use Value: Single-resistor frequency setting simplifies BOM; SYNC input allows coordination with system clock to avoid beat frequencies. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PWM controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UC3845BD1R2G | Fixed 250 kHz oscillator; no integrated boost; no VSEC clamp; 16-pin SOIC; 1.0 V FB reference | Lacks low-VIN gate drive capability and hardware volt-second protection-requires external bias and careful duty cycle limiting | Lower-cost option for non-critical, fixed-input boost/flyback where VIN ≥ 8 V and transformer reset is managed externally |
| LM5039MTX/NOPB | Wide-input (6–100 V), dual-output, current-mode controller; includes adaptive dead-time control; 20-pin TSSOP | Designed for active-clamp forward; lacks BOOST pin but offers higher VIN rating and integrated gate drivers for primary/secondary side | Better suited for high-VIN (>40 V), high-efficiency active-clamp forward designs where secondary-side synchronization is required |
Compared with UC3845BD1R2G and LM5039MTX/NOPB, the LT1950EGN#TRPBF uniquely combines ultra-low VIN start-up (3 V), integrated gate-drive boosting, and programmable volt-second clamping-making it optimal for space-constrained, wide-input forward converters where transformer safety and MOSFET RDS(on) minimization are critical.
Availability
LT1950EGN#TRPBF is available at Aetrix Electronics and suitable for telecom power supplies, automotive DC/DC converters, and isolated medical power systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LT1950EGN#TRPBF 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) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving precision instrumentation, industrial, automotive, and communications markets.
The LT1950EGN#TRPBF belongs to Linear's legacy high-voltage current-mode controller product line, designed specifically for rugged, wide-input isolated and non-isolated DC/DC converters demanding reliable operation from 3 V to 25 V with minimal external components.
FAQ
What is the minimum input voltage required for LT1950EGN#TRPBF to start switching?
The LT1950EGN#TRPBF has a guaranteed minimum start-up voltage of 2.6 V on the VIN pin. However, to achieve full functionality-including activation of the 2.5 V VREF output and enabling of the GATE driver-the VIN2 supply must reach ~6.8 V and ~8 V respectively. When using the internal BOOST converter, LT1950EGN#TRPBF achieves reliable start-up and 10 V gate drive from as low as 3 V VIN, as confirmed in the Electrical Characteristics table and Figure 2 of the datasheet.
How does the VSEC pin function in LT1950EGN#TRPBF, and what voltage range is valid?
The VSEC pin on the LT1950EGN#TRPBF programs the maximum duty cycle as (105/VSEC)%, providing hardware-enforced volt-second clamping essential for forward converter safety. Valid programming range is 1.4 V to 2.8 V, yielding max duty cycles from 75% to 37.5%. If unused, VSEC must be tied to ground to retain the natural ~95% max duty cycle. This behavior is explicitly specified in the Electrical Characteristics table and Applications Information section.
Can LT1950EGN#TRPBF synchronize to an external clock, and what are the limits?
Yes, the LT1950EGN#TRPBF supports synchronization via its SYNC pin, which accepts logic-level signals (10–90% duty) up to 500 kHz. The maximum recommended SYNC frequency is 1.5× the free-running fOSC, and the SYNC input resistance is 20 kΩ with a switching threshold of 1.5–2.2 V. This capability is documented in the Electrical Characteristics table and Block Diagram, enabling EMI reduction and multi-phase coordination.
What is the purpose of the BOOST pin on LT1950EGN#TRPBF, and how is it used?
The BOOST pin on LT1950EGN#TRPBF is the collector output of an internal NPN switch that-when paired with an external inductor, diode, and capacitor-forms an auxiliary boost converter. It generates a regulated 10–11 V supply at VIN2, enabling full 10 V gate drive for external N-MOSFETs even when main VIN is as low as 3 V. This architecture is detailed in Figures 2 and 5 and the "Generating VIN2 Supply Using BOOST Pin" section.
Does LT1950EGN#TRPBF include slope compensation, and how is it adjusted?
Yes, LT1950EGN#TRPBF includes externally adjustable slope compensation via the SLOPE pin. With SLOPE open, default compensation is applied. Connecting a resistor from SLOPE to VREF increases compensation amplitude-e.g., 8 kΩ yields 2× default, 3.3 kΩ yields 3×-preventing subharmonic oscillation at duty cycles above 50%. This adjustability is specified in the Electrical Characteristics table under "Slope Compensation" and explained in the Applications Information section.
LT1950EGN#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-SSOP (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Up, Step-Up/Step-Down
- Output Configuration:
- Positive, Isolation Capable
- Topology:
- Boost, Flyback, Forward Converter, SEPIC
- Number of Outputs:
- 1
- Output Phases:
- 1
- Voltage - Supply (Vcc/Vdd):
- 3V ~ 25V
- Frequency - Switching:
- 100kHz ~ 500kHz
- Duty Cycle (Max):
- 95%
- Synchronous Rectifier:
- No
- Clock Sync:
- Yes
- Serial Interfaces:
- -
- Control Features:
- Enable, Frequency Control
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SSOP
LT1950EGN#TRPBF FAQ
1.How can I place an order for LT1950EGN#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1950EGN#TRPBF 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 LT1950EGN#TRPBF reliable?
The price and inventory of LT1950EGN#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1950EGN#TRPBF is usually 5 days.
3.What payment methods are accepted for LT1950EGN#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1950EGN#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1950EGN#TRPBF?
LT1950EGN#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1950EGN#TRPBF 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 LT1950EGN#TRPBF?
For technical support, including LT1950EGN#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1950EGN#TRPBF requirements.
6.How does Aetrix verify that LT1950EGN#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT1950EGN#TRPBF 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 LT1950EGN#TRPBF meets industry standards.
7.What is the process for return or replacement of LT1950EGN#TRPBF?
All LT1950EGN#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1950EGN#TRPBF, 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 LT1950EGN#TRPBF part is unused and in its original packaging.
Return procedure for LT1950EGN#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT1950EGN#TRPBF Tags
-
UCC28C45DR
Texas Instruments
-
UCC28C40DR
Texas Instruments
-
UCC28C43DR
Texas Instruments
-
ZXSC410E6TA
Diodes Incorporated
-
LM3524DMX/NOPB
Texas Instruments
-
LM3489MMX/NOPB
Texas Instruments
-
MIC2102YML-TR
Microchip Technology
-
LM5148RGYR
Texas Instruments
-
TL598CDR
Texas Instruments
-
LM5155DSSR
Texas Instruments
-
LM25085MYX/NOPB
Texas Instruments
-
UCC2813DTR-0
Texas Instruments
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…
