My Inquiry
My Account
Texas Instruments LM3370SD-4221/NOPB
- Part No.:
- LM3370SD-4221/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 16-WFDFN Exposed Pad
- Datasheet:
-
LM3370SD-4221/NOPB.pdf
- Description:
- IC REG BUCK 1.8V/3.3V DL 16WSON
- Quantity:
- Payment:
- Shipping:
Inventory:917
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM3370SD-4221/NOPB from Texas Instruments is a dual synchronous step-down DC-DC converter with I²C-controlled dynamic voltage scaling, delivering 600 mA per channel at fixed output voltages of 1.8 V (VOUT1) and 3.3 V (VOUT2). It operates from 2.7 V to 5.5 V input, uses internal synchronous rectification, and features 2 MHz fixed-frequency PWM switching with 180° out-of-phase operation for reduced input ripple - deployed in baseband and application processors requiring adaptive power rails.
For engineers reviewing the LM3370SD-4221/NOPB datasheet, LM3370SD-4221/NOPB pinout, LM3370SD-4221/NOPB application, or LM3370SD-4221/NOPB equivalent, key selection criteria include verified I²C register control of VOUT1/VOUT2, confirmed 16-pin WSON (4 mm × 5 mm) package mapping, validated PFM/PWM auto-mode transition thresholds, and documented spread-spectrum noise reduction capability.
Technical Context
The LM3370SD-4221/NOPB implements voltage-mode control with input-voltage feed-forward for stable line regulation across its 2.7–5.5 V input range. Each buck channel integrates PFET/NFET synchronous switches with RDS(on) of 390 mΩ (PFET) and 240 mΩ (NFET) in the WSON package, enabling high efficiency down to light loads via automatic PFM entry below ~66 mA.
Its I²C interface (400 kHz max, 2 kΩ pull-up required) supports real-time reconfiguration of output voltages, forced PWM mode, and spread-spectrum modulation - all coordinated through dedicated EN1/EN2 enables and open-drain nPOR1/nPOR2 reset signals tied to 92% output threshold detection with configurable delay.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage Set | VOUT1 = 1.8 V, VOUT2 = 3.3 V - factory-trimmed fixed outputs; no external resistor divider needed |
| Max Output Current | 600 mA per channel - supports sustained load without thermal shutdown under typical PCB layout (θJA = 26°C/W) |
| Switching Frequency | 2 MHz (typ) - enables use of compact 2.2 µH inductors and 4.7 µF/10 µF ceramic capacitors |
| I²C Interface | 400 kHz compliant - allows dynamic VOUT adjustment, mode control, and spread-spectrum enable/disable |
| Efficiency Peak | ≥90% at 400 mA (VOUT1 = 1.8 V, VIN = 3.6 V) - achieved via synchronous rectification and low RDS(on) FETs |
| Power-On Reset | nPOR1/nPOR2 assert low when output falls to 92% of target - provides sequenced system boot with 50 ms default delay |
| Operating Input Range | 2.7 V to 5.5 V - compatible with single Li-ion, 3-cell NiMH/NiCd, or fixed 3.3 V/5 V rails |
Pinout & Package
LM3370SD-4221/NOPB is packaged in a 16-lead WSON (4 mm × 5 mm × 0.8 mm, package code NHR0016B), with exposed thermal pad for enhanced heat dissipation. Pin functions are electrically isolated between power ground (PGND1/PGND2) and signal ground (SGND), supporting clean analog feedback paths.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN2 | Buck 2 input supply | Accepts 2.7–5.5 V; must be ≥ VOUT2 + 1 V for stable regulation at full load |
| SW2 | Buck 2 switch node | Connects to 2.2 µH inductor; requires low-ESR ceramic capacitor to PGND2 |
| PGND2 | Buck 2 power ground | High-current return path; must be routed separately from SGND to avoid noise coupling |
| VDD | Signal supply | Must be ≥ max(VIN1, VIN2); powers internal logic, I²C interface, and POR circuitry |
| SGND | Signal ground | Reference for FB1/FB2, SDA/SCL, EN1/EN2, and nPOR1/nPOR2; ties to system AGND |
| PGND1 | Buck 1 power ground | High-current return for Buck 1; isolated from PGND2 to minimize cross-channel interference |
| SW1 | Buck 1 switch node | Connects to second 2.2 µH inductor; 180° phase shift reduces input capacitor RMS current |
| VIN1 | Buck 1 input supply | Independent input rail; supports asymmetric input configurations (e.g., VIN1 = 3.3 V, VIN2 = 5 V) |
| FB1 | Buck 1 feedback | Monitors VOUT1 at 1.8 V via internal resistor divider; no external components required |
| SDA | I²C data line | Open-drain; requires 2 kΩ pull-up to VDD; supports read/write of 8-bit VOUT1/VOUT2 registers |
| SCL | I²C clock line | Open-drain; requires 2 kΩ pull-up to VDD; timing complies with standard-mode I²C (400 kHz) |
| nPOR1 | Buck 1 power-on reset | Open-drain active-low; asserts when VOUT1 drops ≤92% of 1.8 V; 100 kΩ pull-up required |
| nPOR2 | Buck 2 power-on reset | Open-drain active-low; asserts when VOUT2 drops ≤92% of 3.3 V; 100 kΩ pull-up required |
| EN1 | Buck 1 enable | Active-high logic input; controls startup sequencing; threshold: VIH ≥ 1.0 V, VIL ≤ 0.4 V |
| EN2 | Buck 2 enable | Active-high logic input; independent control enables staggered power-up for FPGA/CPLD rails |
| FB2 | Buck 2 feedback | Monitors VOUT2 at 3.3 V via internal resistor divider; eliminates need for external resistive network |
Key Features
| Feature | Design Value |
|---|---|
| I²C-controlled dynamic voltage scaling | Enables runtime adjustment of VOUT1 (1.0–2.0 V in 50 mV steps) and VOUT2 (1.8–3.3 V in 100 mV steps) without hardware change |
| Automatic PFM/PWM mode switching | Maintains >85% efficiency at 1 mA load (PFM) and >90% at 400 mA (PWM), eliminating manual mode selection |
| 180° out-of-phase buck operation | Reduces input capacitor RMS current by ~30%, allowing smaller 4.7 µF ceramic input caps instead of larger tantalum |
| Spread-spectrum modulation | Lowers peak EMI by ±12.5 kHz frequency dithering - verified in conducted emissions testing per CISPR 22 Class B |
| Internal soft-start and thermal protection | Prevents inrush current during EN assertion; thermal shutdown engages at 150°C (typ), resumes at 140°C |
| Independent power-on-reset outputs | nPOR1/nPOR2 provide sequenced system reset signals with 50 ms default delay - configurable via I²C register |
Applications
| Baseband Processor Power | Application Processor Core Rail |
|---|---|
Use Scenario: Powers ARM9/ARM11 baseband ICs in 3G/4G mobile handsets where VDD_CORE = 1.8 V and VDD_IO = 3.3 V are required simultaneously. IC Role / Device Role / Timing Role: Dual-output buck regulator providing independent, sequenced, and noise-isolated supplies for RF and digital subsystems. Use Value: Eliminates need for two discrete converters; 180° phase shift cuts input ripple by 40%, reducing EMI filter size and cost. | Use Scenario: Supplies core voltage to multimedia application processors (e.g., OMAP, i.MX) requiring dynamic VDD scaling during video decode/encode bursts. IC Role / Device Role / Timing Role: I²C-programmable voltage source enabling real-time adjustment of VDD_CORE from 1.8 V to 1.2 V during low-power states. Use Value: Reduces processor dynamic power by up to 36% (P ∝ V²) without changing PCB layout or firmware timing constraints. |
| FPGA I/O Bank Supply | CPLD Configuration & Logic Rail |
Use Scenario: Delivers clean 3.3 V to FPGA I/O banks while maintaining 1.8 V for transceiver reference clocks in portable test equipment. IC Role / Device Role / Timing Role: Dual-rail power manager with independent EN1/EN2 pins enabling precise power-up sequencing per Xilinx/Altera guidelines. Use Value: Prevents I/O contention during configuration; nPOR2 ensures FPGA config logic resets only after stable 3.3 V is established. | Use Scenario: Powers CPLD logic fabric (1.8 V) and configuration SRAM (3.3 V) in industrial PLC modules with strict thermal limits. IC Role / Device Role / Timing Role: Thermally optimized dual buck with WSON package and 26°C/W θJA, sustaining 600 mA/channel at 60°C ambient. Use Value: Enables fanless enclosure design; internal thermal shutdown prevents field failure during extended 85°C operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual synchronous buck converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS62400DRVR | Fixed 1.8 V/3.3 V outputs; 3 MHz switching; no I²C interface; uses external feedback resistors | Lacks dynamic voltage scaling; suited for static-rail systems only | Select when I²C control is unnecessary and higher switching frequency is preferred for smaller inductors |
| RT8070ZSP | 1.8 V/3.3 V fixed outputs; 1.5 MHz switching; no I²C; integrated MOSFETs but no spread spectrum | No EMI reduction feature; lower peak efficiency (~88%) at light loads due to lack of PFM mode | Choose for cost-sensitive designs where spread-spectrum and ultra-low IQ (<34 µA) are not required |
Compared with TPS62400DRVR and RT8070ZSP, LM3370SD-4221/NOPB uniquely combines factory-trimmed dual outputs, I²C programmability, spread-spectrum EMI reduction, and verified 34 µA quiescent current in PFM mode - making it optimal for battery-powered systems requiring adaptive power and regulatory compliance.
Availability
LM3370SD-4221/NOPB is available at Aetrix Electronics and suitable for baseband processor power, application processor core rail, FPGA I/O bank supply, and CPLD configuration & logic rail applications requiring stable component supply, long-term lifecycle support, and TI-qualified automotive-grade traceability.
Supply support for LM3370SD-4221/NOPB 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
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management technologies, with over 50 years of innovation in high-efficiency DC-DC conversion.
The LM3370 product line was designed specifically for portable and battery-powered systems requiring dual, dynamically scalable power rails - targeting baseband/application processors, FPGAs, and mixed-signal SoCs with stringent space, efficiency, and EMI constraints.
FAQ
What are the fixed output voltages configured for LM3370SD-4221/NOPB?
The LM3370SD-4221/NOPB is factory-configured with VOUT1 = 1.8 V and VOUT2 = 3.3 V. These values are trimmed internally - no external feedback resistors are required. The "4221" suffix explicitly denotes this voltage combination per TI's ordering matrix, and both outputs remain stable across 2.7–5.5 V input and 0–600 mA load per channel.
Does LM3370SD-4221/NOPB support I²C communication, and what are the interface requirements?
Yes, LM3370SD-4221/NOPB supports standard-mode I²C (up to 400 kHz) via dedicated SDA and SCL pins. Both lines require 2 kΩ pull-up resistors to VDD. The interface enables real-time read/write access to output voltage registers, mode control (PFM/PWM), and spread-spectrum enable - all verified in TI's SNVS406N datasheet Section 8.1.
What package type and thermal characteristics apply to LM3370SD-4221/NOPB?
LM3370SD-4221/NOPB uses the 16-lead WSON package (4 mm × 5 mm × 0.8 mm, NHR0016B). Its junction-to-ambient thermal resistance is 26°C/W on a 4-layer board, enabling 600 mA/channel operation at 60°C ambient without forced airflow. The exposed thermal pad must be soldered to a solid copper pour for optimal performance.
How does the power-on-reset (POR) function work on LM3370SD-4221/NOPB?
LM3370SD-4221/NOPB provides two independent open-drain POR outputs: nPOR1 monitors VOUT1 (1.8 V) and nPOR2 monitors VOUT2 (3.3 V). Each asserts low when its respective output falls to 92% of target. Default delay is 50 ms, but can be trimmed to 50 µs, 100 ms, or 200 ms via I²C register - confirmed in Electrical Characteristics Table 1 and Figure 36.
Can LM3370SD-4221/NOPB operate with different input voltages on VIN1 and VIN2?
Yes, LM3370SD-4221/NOPB supports independent inputs: VIN1 powers Buck 1 and VIN2 powers Buck 2. The datasheet confirms asymmetric operation (e.g., VIN1 = 3.3 V, VIN2 = 5 V) is valid, provided each input stays within 2.7–5.5 V and VDD ≥ max(VIN1, VIN2). This enables flexible power architecture in multi-rail systems.
LM3370SD-4221/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 16-WFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 2
- Voltage - Input (Min):
- 2.7V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 1.8V, 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 600mA
- Frequency - Switching:
- 2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -30°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-WSON (5x4)
LM3370SD-4221/NOPB FAQ
1.How can I place an order for LM3370SD-4221/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3370SD-4221/NOPB 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 LM3370SD-4221/NOPB reliable?
The price and inventory of LM3370SD-4221/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3370SD-4221/NOPB is usually 5 days.
3.What payment methods are accepted for LM3370SD-4221/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3370SD-4221/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3370SD-4221/NOPB?
LM3370SD-4221/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3370SD-4221/NOPB 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 LM3370SD-4221/NOPB?
For technical support, including LM3370SD-4221/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3370SD-4221/NOPB requirements.
6.How does Aetrix verify that LM3370SD-4221/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3370SD-4221/NOPB 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 LM3370SD-4221/NOPB meets industry standards.
7.What is the process for return or replacement of LM3370SD-4221/NOPB?
All LM3370SD-4221/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3370SD-4221/NOPB, 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 LM3370SD-4221/NOPB part is unused and in its original packaging.
Return procedure for LM3370SD-4221/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM3370SD-4221/NOPB 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…
