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reference designSN6505A

Texas Instruments SN6505A

SN6505 Low-Noise 1-A Transformer Drivers for Isolated Power Supplies

Overview

TopologyPush-Pull Converter symmetrical isolated
Input voltage3.3 V
Switching frequency138-203 kHz
Output 15 V / 1 A

Description

The SN6505 is a low-noise, low-EMI push-pull transformer driver, specifically designed for small form factor, isolated power supplies. It drives lowprofile, center-tapped transformers from a 2.25 V to 5 V DC power supply. Ultra-low noise and EMI are achieved by slew rate control of the output switch voltage and through Spread Spectrum Clocking (SSC). The SN6505 consists of an oscillator followed by a gate drive circuit that provides the complementary output signals to drive groundreferenced N-channel power switches. The device includes two 1-A Power-MOSFET switches to ensure start-up under heavy loads. The switching clock can also be provided externally for accurate placement of switcher harmonics, or when operating with multiple transformer drivers. The internal protection features include a 1.7A current limiting, under-voltage lockout, thermal shutdown, and break-before-make circuitry. SN6505 includes a soft-start feature that prevents high inrush current during power up with large load capacitors. The SN6505 is available in a small 6-pin SOT23/DBV package. The device operation is characterized for a temperature range from –55°C to 125°C.

Features

  • Push-Pull Driver for transformers
  • Wide Input Voltage Range: 2.25 V to 5.5 V
  • High Output Drive: 1 A at 5 V Supply
  • Low RON 0.25 Ω Max at 4.5 V Supply
  • Ultra-Low EMI
  • Spread Spectrum Clocking
  • Precision Internal Oscillator Options: 160 kHz (SN6505A) and 420 kHz (SN6505B)
  • Synchronization of Multiple Devices with External Clock Input
  • Slew-Rate Control
  • 1.7 A Current-Limit
  • Low Shutdown Current: <1 μA
  • Thermal Shutdown
  • Wide Temperature Range: –55°C to 125°C
  • Small 6-Pin SOT23/DBV Package
  • Soft Start to reduce In-rush current

Typical applications

  • Process Control, Low-Noise Isolated USB Supplies, Low-Noise Filament Supplies, Telecom Supplies, Distributed Supplies, Radio Supplies, Isolated Power Supply for CAN, RS-485, RS-422, RS-232, SPI, I2C, Low-Power LAN
  • Precision Instruments
  • Medical Instruments

More information

Parts approved by Texas Instruments

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Order Code
Data­sheet
Downloads
Status
Product series
VIN
VOut1(V)
IOut1(A)
Type of Insulation
fswitch(kHz)
∫Udt(Vµs)
NPRI : NSEC
L(µH)
VT(V (AC))
L(mm)
W(mm)
H(mm)
Mount
SamplesAvailability & Sample
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750316029
SPECWE-PPTI Push-Pull Transformers, 3.3 V (DC), 5 V

PCN pending

Due to a pending PCN there will be a new datasheet revision issued for this order code soon. Please find the actual as well based on valid PCN date the new revision datasheet below. If you have further questions please get in contact with our sales staff.

Availability
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Downloads8 files

Status
ActiveProduction is active. Expected lifetime: >10 years.
iProduction is active. Expected lifetime: >10 years.
Product seriesWE-PPTI Push-Pull Transformers
Input Voltage 3.3 V (DC)
Output Voltage 15 V
Output Current 10.6 A
Type of InsulationFunctional 
Switching Frequency 400 - 700
Voltage-µSecond8.9 Vµs
Turns Ratio1:2.1 
Inductance72 µH
Insulation Test Voltage2500 V (AC)
Length8.3 mm
Width12.6 mm
Height4.1 mm
MountSMT 
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