Power Management IC for the SkyBlue™ System

The SKY87021-11 is a high-efficiency RF front-end power management IC for APT RF power amplifier (PA) applications in portable battery powered devices. This IC includes a high-efficiency DC-DC voltage converter capable of delivering 450 mA at 11 V with a 4.5 V reference supply to provide a user-programmable RF PA APT supply for a 2.5 V to 5.5 V input range.

The SKY87021-11 also provides an additional 4.5 V bias supply for RF PA operation. This bias voltage output can supply load currents up to 3 mA and is available whenever the device is enabled. When the device is disabled, the 4.5 V bias supply is shut down. This device has over-voltage, over-current, shorted circuit, and thermal shutdown protection to protect the device and system under adverse operating conditions.

The SKY87021-11 is capable of supporting HPUE front-end modules and is controlled with a MIPI RFFE 2.0 compliant interface with 8-bit output voltage programming resolution.

The SKY87021-11 is available in a 16-pin, 1.991 mm x 1.991 mm Chip Scale Package (CSP).


Min. VIN (V)2.5
Max. VIN (V)5.5
Min. VOUT (V)2.5
Max. VOUT (V)VccPA
Typ. IQ (μA)TBD
PackageCSP, 16-ball
Package (mm)1.991 x 1.991 x 0.695


  • Input voltage range: 2.5 V to 5.5 V
  • High voltage boost supply:
    • Output voltage range from Bypass to 11V
    • Output current up to 450mA
    • High efficiency: 90% typical (VIN=3.8 V, VOUT=9.5 V, ILOAD>110 mA)
    • Fast voltage transition response 570 mV/μs
    • Optimized for small external components
      • For HPUE application, 1.5 μH inductor, 2x1.0 μF output capacitor
      • For non-HPUE application: 1.5 μH/2.2 μH, 1.0 μF output capacitor
      • High 2.25 MHz switching frequency
    • Shutdown load disconnect
    • Fast load transient response, less than 20 μs
    • Over temperature, over voltage and short circuit protection
  • Low voltage ÷2 step-down function: Output current up to 30 mA
  • 4.5 V, 3 mA PA bias supply output
  • MIPI RFFE interface for setup and control: 8-bit output voltage programming resolution
  • Small footprint CSP (16-ball, 1.991 mm x 1.991 mm) package (MSL1, 260 °C per JEDEC J-STD-020)

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