Mini-Circuits PWR-SEN-6G+

Mini-Circuits PWR-SEN-6G+

This post is about the Mini-Circuits USB power sensor

Inside view of the power head

Components

CY7C63743    CYPRESS enCoRe™ USB Combination Low-Speed USB and PS/2 Peripheral Controller

24LC512    512K I2C™ Serial EEPROM (Address: 0xA8)

ADR431    Ultralow Noise XFET Voltage References with Current Sink and Source Capability

AD7414    ±0.5°C Accurate, 10-Bit Digital Temperature Sensor, I2C

AD7791    Low Power, Buffered 24-Bit Sigma-Delta ADC, SPI

SMS7630-079LF    SKYWORKS RF Schottky Diode

(not 100% sure! Marking: Anode)

How does it work?

The 5 resistors at the input form a combined 3dB resistive pad and RF termination. The RF diode (SMS7630-079LF) rectifies the signal, the capacitors on the DC side form a broadband shortcircuit for RF. Having the different capacitance values in the arrangement shown above (the pF very close to the diode) is very important for a flat frequency response.

USB Interface and Software

USB Interface information:

Bus 002 Device 009: ID 0fc5:1222 Delcom Engineering I/O Development Board
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               1.00
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0         8
  idVendor           0x0fc5 Delcom Engineering
  idProduct          0x1222 I/O Development Board
  bcdDevice            0.11
  iManufacturer           1 MINI-CIRCUITS 
  iProduct                2 USB POWER SENSOR
  iSerial                 0 
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           18
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              250mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass         0 (Defined at Interface level)
      bInterfaceSubClass      0 
      bInterfaceProtocol      0 
      iInterface              0 
Device Status:     0x0002
  (Bus Powered)
  Remote Wakeup Enabled

The uC is a Delcom USB Generation I controller (802670 USB G1 LS 16 IO CHIP SOIC24) which does require custom Delcom IO driver. Generation II uses USB HID driver instead.