My Inquiry
My Account
Analog Devices Inc. LT1533CS#PBF
- Part No.:
- LT1533CS#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LT1533CS#PBF.pdf
- Description:
- IC REG PUSH-PULL ADJ 1A 16SO
- Quantity:
- Payment:
- Shipping:
Inventory:1,291
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT1533CS#PBF from Analog Devices (formerly Linear Technology) is a dual-output, current-mode switching regulator IC designed for ultralow-noise power conversion in precision analog systems. It integrates two 1A current-limited NPN power switches, independently programmable voltage and current slew rates (11 V/µs rising, 14.5 V/µs falling; 1.3 A/µs both edges), 20–250 kHz oscillator with external sync capability, and dual-polarity feedback (1.25 V positive / –2.5 V negative reference) - enabling low-EMI ±12V isolated supplies for medical instrumentation.
For engineers reviewing the LT1533CS#PBF datasheet, LT1533CS#PBF pinout, LT1533CS#PBF application, or LT1533CS#PBF equivalent, key selection considerations include slew-controlled EMI reduction (<100 µVP-P noise), dual-rail regulation capability, 2.7–23 V input range, 12 µA shutdown current, and SO-16 narrow package thermal performance (θJA = 100°C/W).
Technical Context
The LT1533CS#PBF employs fixed-frequency current-mode control with internal slope compensation, enabling stable operation up to 45.5% duty cycle (or forced 50% via DUTY pin). Its dual out-of-phase switch drivers support push-pull transformer topologies, while independent RVSL/RCSL pins allow precise tuning of collector voltage dV/dt and emitter current dI/dt to suppress high-frequency harmonic content by up to 40 dB.
Regulation is achieved through transconductance error amplifiers (gm = 1.5 m℧ typ) referenced to 1.25 V (FB) and –2.5 V (NFB), with VC pin serving as loop compensation node, current limit threshold, and soft-start interface. Protection includes cycle-by-cycle current limiting, thermal shutdown at 125°C, and undervoltage lockout below 2.55 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.7 V to 23 V - supports wide-input industrial and battery-backed systems without pre-regulation. |
| Output Switch Current | 2 × 1 A - enables dual-rail or parallel configurations for up to 2 A total load in push-pull or boost topologies. |
| Oscillator Frequency | 20 kHz to 250 kHz - user-adjustable via RT/CT; synchronizable externally to place harmonics away from sensitive bands. |
| Voltage Slew Rate | 11 V/µs (rising), 14.5 V/µs (falling) - programmable via RVSL resistor to reduce radiated EMI without sacrificing efficiency. |
| Current Slew Rate | 1.3 A/µs (both edges) - set by RCSL to minimize conducted EMI from fast di/dt transients. |
| Shutdown Current | 12 µA typical - ensures minimal battery drain in portable instrumentation during sleep mode. |
| Reference Voltages | +1.25 V (FB), –2.5 V (NFB) - enables direct regulation of both positive and negative outputs without external op-amps. |
Pinout & Package
LT1533CS#PBF is housed in a 16-pin narrow SOIC (SO-16) package with exposed pad not present; thermal resistance θJA = 100°C/W. Pin functions are validated per Linear Technology's official datasheet revision (DC2019).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| COL A (2), COL B (15) | Power switch collectors | Alternately driven NPN outputs; tied together for boost, used differentially for push-pull transformers. |
| FB (7), NFB (8) | Positive/negative feedback inputs | FB regulates +VOUT to 1.25 V; NFB regulates –VOUT to –2.5 V - enabling true dual-polarity output control. |
| RVSL (13), RCSL (12) | Slew rate programming inputs | Resistors to ground set voltage (220/RVSL kΩ) and current (33/RCSL kΩ) slew rates - primary EMI tuning interface. |
| VC (10) | Error amplifier output / compensation node | Integrates FB/NFB error; connects to RC network for loop stability; clamped to adjust current limit or enable soft-start. |
| PGND (16) | Power switch emitter return | Must be connected with ~25 nH inductance (e.g., 1" trace) to stabilize slew control loop during turn-off. |
Key Features
| Feature | Design Value |
|---|---|
| Ultralow EMI noise | <100 µVP-P output ripple (100 MHz BW) - achieved via independent dV/dt and di/dt control, eliminating need for bulky EMI filters. |
| Dual polarity regulation | Simultaneous +1.25 V and –2.5 V references - allows single IC to regulate split-rail supplies without external amplifiers or level shifters. |
| External clock synchronization | SYNC pin accepts square wave ≥1.4 V - enables precise harmonic placement to avoid interference with ADC sampling clocks or RF bands. |
| 50% forced duty cycle mode | DUTY pin grounded locks outputs to exact 50% duty cycle at half oscillator frequency - ideal for unregulated forward or push-pull transformer drive. |
| Thermal & fault protection | Integrated thermal shutdown, cycle-by-cycle current limit, and UVLO - prevents damage during overload, short-circuit, or ambient overheating without external circuitry. |
Applications
| Precision Instrumentation Systems | Isolated Supplies for Industrial Automation |
|---|---|
Use Scenario: Low-noise ±15 V supply for 24-bit delta-sigma ADC front-end in portable data loggers. IC Role / Device Role / Timing Role: Dual-output switching regulator providing tightly regulated, slew-controlled rails to minimize PSRR-induced measurement errors. Use Value: Achieves <100 µVP-P noise floor - preserves ENOB in high-resolution analog signal chains where conventional switchers degrade SNR. | Use Scenario: Galvanically isolated ±12 V bias for PLC I/O modules operating in electrically noisy factory environments. IC Role / Device Role / Timing Role: Push-pull DC/DC controller driving center-tapped transformer with synchronized switching to suppress common-mode EMI coupling into field wiring. Use Value: Reduces conducted emissions by 40 dB - meets CISPR 11 Class A limits without ferrite beads or shielding, lowering BOM cost and board area. |
| Medical Instruments | Wireless Communications |
Use Scenario: Battery-powered ECG amplifier requiring ultraquiet ±5 V rails with <1 µV RMS noise in 0.05–150 Hz band. IC Role / Device Role / Timing Role: Low-EMI regulator supplying analog front-end; slew rates tuned to avoid interference with physiological signal acquisition windows. Use Value: Eliminates switching artifacts in raw ECG traces - avoids post-processing filtering that could distort ST-segment morphology. | Use Scenario: Compact 3.3 V to 5 V boost converter for LTE modem PA bias in space-constrained IoT gateways. IC Role / Device Role / Timing Role: Single-switch boost configuration (COL A + COL B paralleled) with 50% duty cycle mode for stable unregulated output under dynamic load. Use Value: Delivers 1 A at >88% efficiency with <200 mVP-P ripple - sustains PA linearity across 100 MHz–2.7 GHz bandwidth without spectral regrowth. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-output, low-EMI switching regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3892-2 | Higher VIN max (60 V), integrated MOSFET drivers, no slew control - relies on spread-spectrum and layout for EMI reduction. | Targeted at automotive 12 V/24 V systems; lacks independent dV/dt/di/dt tuning for precision analog noise suppression. | Select when input exceeds 23 V or when MOSFET gate drive integration reduces component count - not suitable for sub-100 µVP-P noise requirements. |
| TPS54A20 | Single-output, 2 A buck controller; includes integrated FETs but no negative rail support or slew programming pins. | Designed for point-of-load digital supply rails; cannot replace dual-polarity regulation or push-pull transformer drive. | Choose for high-efficiency 1–3 A single-rail conversion where EMI is managed via PCB layout - not a functional substitute for LT1533CS#PBF's core capabilities. |
Compared with LTC3892-2 and TPS54A20, the LT1533CS#PBF uniquely delivers programmable slew control for EMI reduction, native dual-polarity feedback, and push-pull topology support - making it irreplaceable in applications demanding verified <100 µVP-P noise and ±VOUT regulation from a single IC.
Availability
LT1533CS#PBF is available at Aetrix Electronics and suitable for precision instrumentation systems, isolated industrial supplies, and medical-grade power conversion requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.
Supply support for LT1533CS#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 documentation, and application engineering for legacy Linear parts including the LT1533 series.
The LT1533CS#PBF belongs to Linear's ultralow-noise switching regulator product line, engineered specifically for EMI-sensitive analog systems where traditional switchers compromise signal integrity - emphasizing slew-controlled harmonic suppression over raw efficiency.
FAQ
What is the maximum allowable input voltage for the LT1533CS#PBF?
The LT1533CS#PBF has an absolute maximum input voltage rating of 30 V on the VIN pin, but its recommended operating range is 2.7 V to 23 V. Operation above 23 V risks exceeding safe junction temperature or violating internal LDO headroom, potentially causing regulation loss or premature thermal shutdown. The LT1533CS#PBF must not be operated continuously at 30 V.
Can the LT1533CS#PBF regulate both positive and negative output voltages simultaneously?
Yes, the LT1533CS#PBF supports simultaneous regulation of positive and negative outputs using its dedicated FB (1.25 V reference) and NFB (–2.5 V reference) pins. When both pins are actively used with separate resistor dividers, the IC prevents either rail from overvoltage - though light-load regulation accuracy degrades due to competition between feedback paths. This dual-sensing mode is validated in the LT1533CS#PBF datasheet Figure 2.
How does the slew rate control function in the LT1533CS#PBF reduce EMI?
The LT1533CS#PBF reduces EMI by allowing independent adjustment of output voltage slew rate (via RVSL) and output current slew rate (via RCSL), directly suppressing high-frequency harmonic energy in both conducted and radiated spectra. Measured results show up to 40 dB reduction in harmonic power above 10 MHz compared to conventional switchers - a feature confirmed in LT1533CS#PBF Typical Application TA02.
What is the purpose of the PGND pin on the LT1533CS#PBF, and why is 25 nH inductance specified?
The PGND pin on the LT1533CS#PBF serves as the return path for both power switches' emitters and must be connected with approximately 25 nH inductance (e.g., 1" PCB trace) to stabilize the current slew control loop during switch turn-off. Less than 25 nH causes instability in slew edge shaping; more than 50 nH induces oscillation on voltage slew edges - a requirement explicitly defined in the LT1533CS#PBF Pin Functions section.
Does the LT1533CS#PBF support external synchronization of its oscillator, and what are the timing constraints?
Yes, the LT1533CS#PBF supports external oscillator synchronization via the SYNC pin, which accepts square-wave inputs ≥1.4 V amplitude. The rising edge triggers oscillator discharge, and minimum pulse width is 0.5 µs. Sync frequency must not exceed 1.5× the free-running oscillator frequency to avoid subharmonic oscillation - a constraint documented in the LT1533CS#PBF Applications Information section on Oscillator Sync.
LT1533CS#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Up/Step-Down
- Output Configuration:
- Positive or Negative, Isolation Capable
- Topology:
- Push-Pull
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2.7V
- Voltage - Input (Max):
- 23V
- Voltage - Output (Min/Fixed):
- 1.25V
- Voltage - Output (Max):
- 30V (Switch)
- Current - Output:
- 1A (Switch)
- Frequency - Switching:
- 20kHz ~ 250kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 100°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SO
LT1533CS#PBF FAQ
1.How can I place an order for LT1533CS#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1533CS#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 LT1533CS#PBF reliable?
The price and inventory of LT1533CS#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1533CS#PBF is usually 5 days.
3.What payment methods are accepted for LT1533CS#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1533CS#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1533CS#PBF?
LT1533CS#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1533CS#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 LT1533CS#PBF?
For technical support, including LT1533CS#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1533CS#PBF requirements.
6.How does Aetrix verify that LT1533CS#PBF is sourced from the original manufacturer or authorized distributors?
All LT1533CS#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 LT1533CS#PBF meets industry standards.
7.What is the process for return or replacement of LT1533CS#PBF?
All LT1533CS#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1533CS#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 LT1533CS#PBF part is unused and in its original packaging.
Return procedure for LT1533CS#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT1533CS#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…
