SLVUB50C June   2017  – March 2019 UCD90120A , UCD90124A , UCD90160 , UCD90160A , UCD90240 , UCD90320 , UCD90320U , UCD9090 , UCD9090-Q1 , UCD9090A , UCD90910

 

  1.   UCD90xxx Sequencer Schematics Guidelines
    1. 1 Introduction
    2. 2 UCD Power Supply Review
      1. 2.1 UCD90240, UCD90320 and UCD90320U
      2. 2.2 Remaining UCD90xxx Devices
    3. 3 I/O Signals Review
      1. 3.1 Analog Monitor (MONx/AMONx) Pin Review
      2. 3.2 PMBUS Signals Review
      3. 3.3 GPIO Pins Review
      4. 3.4 Margin Pins Review
      5.      Trademarks
  2.   Revision History

3.1 Analog Monitor (MONx/AMONx) Pin Review

The following list provides analog monitor (MONx/AMONx) pin information:

  • Internal or external voltage reference is used by ADC to monitor the external signal. Be sure to have the proper voltage divider to limit the input signal.

    • Table 1. UCD90xxx Voltage References

    UCD90240, UCD90320 and UCD90320U Remaining UCD90xxx Devices
    Internal Voltage Reference V33D 2.5 V
    External Voltage Reference 2.4–3 V N/A
  • When a digital signal is connected to the analog monitor (MONx/AMONx) pin, please check the logic level of the input signal to see whether it is over the voltage reference
  • TI recommends having a 10-nF to 100-nF decoupling capacitor close to the analog monitor (MONx/AMONx) pin to remove rail ripple voltage
  • For UCD90240,UCD90320 and UCD90320U, TI recommends maintaining at least a 200-Ω resistance between a low-impedance analog input and an AMON pin. For example, when monitoring a rail voltage without a resistor divider, place a 200-Ω resistor in series between the rail output and AMON pin, as shown in Figure 2.
  • Ground unused MONx/AMONx pins to save power consumption and decrease EMI.