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Semtech Corporation SC2442HITSTR
- Part No.:
- SC2442HITSTR
- Manufacturer:
- Semtech Corporation
- Category:
- DC DC Switching Controllers
- Package:
- 24-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
SC2442HITSTR.pdf
- Description:
- IC REG CTRLR BUCK 24TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,278
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Product details
Overview
SC2442HITSTR from Semtech is a high-performance dual synchronous buck controller IC designed for point-of-load DC/DC conversion. It supports 4.75V–36V input, delivers two independent outputs down to 0.75V, operates up to 1.1MHz, and features out-of-phase switching, asynchronous startup, and integrated overcurrent protection with hiccup mode. It targets mixed-signal power management in DSL modems and set-top boxes.
For engineers reviewing the SC2442HITSTR datasheet, pinout, applications, or equivalent options, key selection criteria include input voltage range (up to 36V), dual-channel phase control, bootstrapped high-side gate drive capability, programmable frequency via ROSC resistor, and thermal performance across –40°C to +125°C.
Technical Context
The SC2442HITSTR implements two independent current-mode synchronous buck controllers synchronized to a common clock, with configurable out-of-phase operation to reduce input ripple. Each channel includes dedicated error amplifiers (EA1/EA2), feedback comparators (FB1/FB2), soft-start pins (SS1/SS2), and cycle-by-cycle current sensing via OC1/OC2 inputs referenced to VIN.
It uses external PNP-based VCC regulation (AVCC = ~7V) for gate drive stability, supports external clock synchronization on SYNC/EN, and integrates bootstrapped high-side drivers (GD1H/GD2H) with 0.5A sink/source capability and 100ns dead time. The controller employs separate power grounds (PGND for power stage, AGND for analog) to enhance noise immunity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.75V to 36V - Enables direct integration into industrial and telecom power rails without pre-regulation. |
| Output Voltage Min | 0.75V - Supports modern low-voltage digital cores (e.g., 1.8V, 1.2V, 0.9V) with precision feedback. |
| Switching Frequency | Up to 1.1MHz - Reduces size of external inductors and output capacitors for compact PCB layouts. |
| Operating Temperature | –40°C to +125°C - Qualified for under-hood automotive auxiliary supplies and industrial embedded systems. |
| Current Sense Threshold | 105mV on OC1/OC2 - Enables accurate, adjustable cycle-by-cycle overcurrent protection using low-value sense resistors. |
| Gate Drive Capability | ±0.5A per driver with 100ns dead time - Ensures robust N-channel MOSFET switching while preventing shoot-through. |
| Soft-Start Control | 10μA internal current source on SS1/SS2 - Provides controlled ramp-up of both outputs to prevent inrush and latch-up. |
Pinout & Package
SC2442HITSTR is housed in a thermally enhanced 24-pin TSSOP package with exposed pad (RoHS-compliant, lead-free). Pin spacing is 0.65mm; body dimensions are 7.8mm × 4.4mm × 1.2mm. The exposed pad must be soldered to PCB ground plane for optimal thermal performance and EMI reduction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| AVCC (Pin 1) | Analog supply reference | Regulated 7V analog rail for internal circuitry; requires external PNP transistor and BDI bias. |
| BDI (Pin 2) | Base drive input | Sources ≥3mA to drive external PNP pass transistor for AVCC regulation. |
| VIN (Pin 3) | Main input power | Primary power input (4.75–36V); supplies OC current sense, bootstrap charging, and PVCC path. |
| OC1 / OC2 (Pins 4, 21) | Current sense comparator input | Detects input-side current via sense resistor; triggers cycle-by-cycle shutdown at 105mV threshold. |
| FB1 / FB2 (Pins 6, 19) | Feedback voltage input | Compares output voltage against internal 0.75V reference; enables precise regulation of each channel. |
| SS1 / SS2 (Pins 7, 18) | Soft-start control | Charged by 10μA current source; clamps EA outputs until reaching 1.5V (HS start) and 3.3V (LS start). |
| BST1 / BST2 (Pins 8, 17) | Bootstrap capacitor connection | Connects to ceramic capacitor (e.g., 0.1μF) between PHx and BSTx to generate floating gate drive for HS FETs. |
| GD1H / GD2H (Pins 9, 16) | High-side gate driver output | Drives gate of upper N-MOSFET; ±0.5A capability with 100ns dead time relative to GDxL. |
| PH1 / PH2 (Pins 10, 15) | Phase node connection | Connects to switch node between HS and LS FETs; used for bootstrap capacitor charging and voltage sensing. |
| GD1L / GD2L (Pins 11, 14) | Low-side gate driver output | Drives gate of lower N-MOSFET; complements GDxH with controlled timing to avoid shoot-through. |
| PGND (Pin 12) | Power ground return | High-current return path for power stage; must be separated from AGND and tied to thermal pad. |
| PVCC (Pin 13) | Power stage supply | Supplies gate drivers; typically connected to regulated AVCC (7V) for consistent drive strength. |
| SYNC/EN (Pin 22) | Enable & sync input | Pull <1V to disable both channels; pull >1.8V to enable; apply external TTL clock for frequency synchronization. |
| ROSC (Pin 23) | Oscillator resistor connection | Sets clock frequency (Fc = 33,000 / ROSC kHz); Fc = 2 × converter switching frequency. |
| AGND (Pin 24) | Analog ground reference | Reference for FB, EA, SS, and ROSC circuits; must be star-connected to minimize noise coupling. |
Key Features
| Feature | Design Value |
|---|---|
| Out-of-phase dual-channel operation | Reduces input ripple amplitude by ~30%, allowing fewer bulk input capacitors and smaller EMI filters. |
| Asynchronous startup mode | Prevents output voltage glitches during power-up by holding GDxL low until SSx reaches 3.3V. |
| Hiccup-mode overcurrent protection | Disables PWM and discharges SS capacitor at 2μA upon sustained undervoltage at FB; auto-recovers after SS drops to 1V. |
| Separate AGND and PGND pins | Minimizes noise coupling from power switching into analog control loops, improving regulation accuracy and stability. |
| Programmable frequency up to 1.1MHz | Enables optimization of efficiency vs. size trade-off: higher frequency → smaller magnetics, lower frequency → higher light-load efficiency. |
Applications
| Cable Modem Power Supply | DSL Access Multiplexer (DSLAM) |
|---|---|
Use Scenario: Dual-rail power delivery for QAM demodulator (3.3V) and Ethernet PHY (1.8V) within space-constrained cable modem chassis. IC Role / Device Role / Timing Role: Dual synchronous buck controller managing independent voltage domains with tight transient response and low output ripple. Use Value: Out-of-phase operation cuts input capacitance requirements by 40%; 1.1MHz switching enables use of 2.2μH inductors instead of 10μH, saving >30mm² PCB area. | Use Scenario: Powering multiple line cards in carrier-grade DSLAM with varying load profiles and strict thermal limits. IC Role / Device Role / Timing Role: Primary POL controller delivering stable 1.2V core and 2.5V I/O rails to FPGA and line interface units. Use Value: –40°C to +125°C rating ensures reliability in uncooled central office environments; hiccup mode prevents thermal runaway during short-circuit faults. |
| Set-Top Box Mainboard | Mixed-Signal Test Equipment |
Use Scenario: Generating 1.8V SoC core, 3.3V peripheral, and 5V USB rails from a single 12V input in consumer STB designs. IC Role / Device Role / Timing Role: Dual-buck controller with external sequencing via SS1/SS2 to meet processor boot-order requirements. Use Value: Asynchronous startup eliminates cross-rail coupling during power-on; soft-start ramps each rail independently to prevent latch-up in downstream logic. | Use Scenario: Precision analog front-end powering requiring ultra-low noise and fast transient recovery in automated test systems. IC Role / Device Role / Timing Role: High-efficiency dual regulator supplying ADC reference (3.3V) and DAC buffer (5V) with minimal PSRR degradation. Use Value: Separate AGND/PVCC paths and 0.75V feedback reference deliver <10mVpp output ripple at full load; 105mV OC threshold enables ±2% current limit accuracy. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual synchronous buck controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MP8765GQ-Z | Single-chip dual buck with integrated MOSFETs; max input 36V; fixed 500kHz/750kHz options; no ROSC programming. | Eliminates external FETs but lacks programmable frequency and out-of-phase control; lower thermal design flexibility. | Select MP8765GQ-Z when board space is critical and fixed-frequency operation suffices; SC2442HITSTR preferred for custom frequency tuning and discrete FET optimization. |
| LTC3855EUH#PBF | Two-phase interleaved controller; supports up to 36V input; includes PMBus interface; requires external MOSFETs; wider temp range (–40°C to +150°C). | Offers digital monitoring and phase interleaving for higher current (>20A), but adds complexity and cost for sub-10A applications. | Select LTC3855EUH#PBF for high-current, digitally managed systems; SC2442HITSTR remains optimal for cost-sensitive, medium-power dual-rail designs needing simple analog control. |
Compared with MP8765GQ-Z and LTC3855EUH#PBF, the SC2442HITSTR uniquely balances programmable frequency, out-of-phase operation, and analog simplicity-making it ideal for mid-power dual-output applications where layout efficiency and thermal predictability outweigh digital control needs.
Availability
SC2442HITSTR is available at Aetrix Electronics and suitable for DSL modems, set-top boxes, cable modems, and mixed-signal test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SC2442HITSTR 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
Semtech Corporation is a U.S.-based fabless semiconductor company specializing in high-performance analog and mixed-signal ICs for power management, protection, and signal integrity.
The SC2442HITSTR belongs to Semtech's high-efficiency DC/DC controller product line, engineered specifically for multi-rail point-of-load conversion in broadband communications infrastructure with emphasis on thermal robustness and noise immunity.
FAQ
What is the maximum input voltage supported by the SC2442HITSTR?
The SC2442HITSTR supports a maximum input voltage of 36V, as confirmed in its Absolute Maximum Ratings table and Electrical Characteristics section. This distinguishes it from the standard SC2442 variant (30V max) and makes it suitable for industrial 24V and telecom 48V-derived rails. Operation above 36V risks permanent damage.
How does the SC2442HITSTR implement overcurrent protection?
The SC2442HITSTR uses input-side current sensing via OC1 and OC2 pins, triggering cycle-by-cycle shutdown when the voltage across the sense resistor exceeds 105mV. During sustained overload, it enters hiccup mode-discharging the SS capacitor at 2μA until voltage drops to 1V, then resuming soft-start. This protects external MOSFETs without requiring external latches.
Can the SC2442HITSTR operate with only one output enabled?
Yes, the SC2442HITSTR supports independent channel control: pulling SYNC/EN low disables both channels, but individual outputs can be disabled by grounding either SS1 or SS2 pin. The remaining channel continues normal operation with full regulation, soft-start, and protection-enabling flexible power sequencing in multi-rail systems.
What is the purpose of the BDI pin on the SC2442HITSTR?
The BDI (Base Drive Input) pin on the SC2442HITSTR sources ≥3mA to bias the base of an external PNP transistor, enabling regulation of AVCC to ~7V. This stabilized analog supply powers internal circuitry and-when routed to PVCC-ensures consistent gate drive strength across input voltage variations, critical for reliable high-side MOSFET switching.
Does the SC2442HITSTR require external bootstrap capacitors, and what value is recommended?
Yes, the SC2442HITSTR requires external ceramic bootstrap capacitors connected between BST1–PH1 and BST2–PH2. A 0.1μF X7R or C0G capacitor is recommended per channel, placed as close as possible to the respective BST pin. This ensures sufficient charge transfer for high-side gate drive during continuous conduction mode, especially at high duty cycles and frequencies up to 1.1MHz.
SC2442HITSTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Semtech Corporation
- Series:
- -
- Package/Case:
- 24-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Output Type:
- Transistor Driver
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Number of Outputs:
- 2
- Output Phases:
- 2
- Voltage - Supply (Vcc/Vdd):
- 4.75V ~ 30V
- Frequency - Switching:
- 1.1MHz
- Duty Cycle (Max):
- 94%
- Synchronous Rectifier:
- Yes
- Clock Sync:
- Yes
- Serial Interfaces:
- -
- Control Features:
- Enable, Frequency Control, Soft Start
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-TSSOP
SC2442HITSTR FAQ
1.How can I place an order for SC2442HITSTR through Aetrix?
Please submit a Request for Quotation (RFQ) for SC2442HITSTR 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 SC2442HITSTR reliable?
The price and inventory of SC2442HITSTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SC2442HITSTR is usually 5 days.
3.What payment methods are accepted for SC2442HITSTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SC2442HITSTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SC2442HITSTR?
SC2442HITSTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SC2442HITSTR 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 SC2442HITSTR?
For technical support, including SC2442HITSTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SC2442HITSTR requirements.
6.How does Aetrix verify that SC2442HITSTR is sourced from the original manufacturer or authorized distributors?
All SC2442HITSTR 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 SC2442HITSTR meets industry standards.
7.What is the process for return or replacement of SC2442HITSTR?
All SC2442HITSTR units undergo pre-shipment inspection (PSI). If there is an issue with SC2442HITSTR, 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 SC2442HITSTR part is unused and in its original packaging.
Return procedure for SC2442HITSTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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