The KTS1690A is a low-resistance load switch with adjustable current limit, soft-start, fast turn ON mode, “ideal diode” reverse current protection, and integrated TVS. It is optimized to protect systems with USB type-C ports that source up to 15W at 5V and must withstand up to 29V on VBUS (OUT pin).

The KTS1690A uses an external resistor to set the current limit from 400mA to 3.7A.

Soft-start limits inrush current, while the FON logic input enables fast turn ON mode for USB fast role swap (FRS). Automatic “ideal diode” reverse current protection (RCP) isolates the system’s 5V internal rail whenever VBUS (OUT pin) is driven to a higher voltage, as when charging. The integrated TVS provides IEC Standards ±8kV ESD contact, ±15kV ESD air gap, and ±80V surge ratings for robust system protection. A FLT flag indicates an over-current or over-temperature fault condition.

The KTS1690A is available in advanced, fully “green” compliant, 1.98 x 1.98mm, 16-bump Wafer-Level Chip Scale Package (WLCSP).


  • 2.5V to 5.5V Supply Voltage Range at IN
  • 29V Abs. Max. Rating at OUT
    • 80V Surge Protection (IEC61000-4-5)
    • 8kV ESD Contact Discharge (IEC61000-4-2)
    • 15kV ESD Air Gap Discharge (IEC61000-4-2)
  • 35mΩ typ. On-Resistance from IN to OUT
  • Adjustable Current Limit Protection (CLP)
    • 400mA to 3.3A via RISET
  • Over-Current Protection (OCP)
  • Short-Circuit Protection (SCP)
  • “Ideal Diode” Reverse Current Protection (RCP)
  • Over Temperature Protection (OTP)
  • Soft-Start (SS) Limits Inrush Current
  • Fast Turn ON supports USB Fast Role Swap (FRS)
  • Open-Drain FLT Flag
  • Safety approvals
    • UL 2367, file no. E515099
  • -40°C to 85°C Operating Temperature Range
  • 16-bump WLCSP 1.98 x 1.98mm (0.5mm pitch)


  • Notebooks, Ultra-Books, Desktop PCs
  • Smartphones, Tablets, Gaming Consoles
  • Set-Top Box, Networking, any USB ISOURCE Port

Packaging Information

Package Dimensions Bumps Package Code
WLCSP44-16 1,98mm x 1.98mm x 0.50mm 16 GAA


Vin (min)  Vin (max)  ON Resistance (mΩ) Max Current (A)
2.5V 5.5V 30mΩ 3.3A

Technical Documentation

Description Documents Type
Package Outline DrawingWLCSP44-16 GAA PODPDF

Evaluation Tools

Documents Type
User ManualPDF
Quick Start GuidePDF
Bill of MaterialsXLSX
3D BoardPDF


Part Number Marking Operating Temperature Package
Purchase Options
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