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2. In accordance with the "IEEE1149.1" standard the pads TDI, TMS, TCK and TRST are input pads
with an internal pull-up transistor and TDO is a 3-state output pad.
3. For board design without boundary scan implementation connect the TRST pin to ground.
4. This pin provides easy initialization of the Boundary Scan Test (BST) circuit. TRST can be used to
force the Test Access Port (TAP) controller to the TEST_LOGIC_RESET state (normal operation) at
once.
5. Pin strapping is done by connecting the pin to the supply via a 3.3 κΩ resistor. During the power-up
reset sequence the corresponding pins are switched to input mode to read the strapping level. For the
default setting no strapping
resistor is necessary (internal pull-down).
6. Pin RTCO operates as I 2 C-bus slave address pin; RTCO = 0 slave address 42H/43H (default);
RTCO = 1 slave address 40H/41H.
7. Pin ALRCLK: 0 = 24.576 MHz crystal (default; Philips order number 4322 143 05291); 1 = 32.110
MHz crystal
9.17. TPS72501
9.17.1. General Description
The TPS725xx family of 1-A low-dropout (LDO) linear regulators has fixed voltage options available that
are commonly used to power the latest DSPs, FPGAs, and microcontrollers. An adjustable option
ranging from 1.22 V to 5.5 V is also available. The integrated supervisory circuitry provides an active
low RESET signal when the output falls out of regulation. The no capacitor/any capacitor feature allows
the customer to tailor output transient performance as needed. Therefore, compared to other regulators
capable of providing the same output current, this family of regulators can provide a stand alone power
supply solution or a post regulator for a switch mode power supply.
These regulators are ideal for higher current applications. The family operates over a wide range of
input voltages (1.8 V to 6 V) and has very low dropout (170 mV at 1-A).
Ground current is typically 210 µA at full load and drops to less than 80 µA at no load. Standby current
is less than 1 µA.
Each regulator option is available in either a SOT223–5, D (TPS72501 only), or DDPAK package. With
a low input voltage and properly heatsinked package, the regulator dissipates more power and
achieves higher efficiencies than similar regulators requiring 2.5 V or more minimum input voltage and
higher quiescent currents. These features make it a viable power supply solution for portable, battery
powered equipment.
Although an output capacitor is not required for stability, transient response and output noise are
improved with a 10-µF output capacitor.
Unlike some regulators that have a minimum current requirement, the TPS725 family is stable with no
output load current. The low noise capability of this family, coupled with its high current operation and
ease of power dissipation, make it ideal for telecom boards, modem banks, and other noise sensitive
applications.
9.17.2. Features
• 1-A Output Current
• Available in 1.5-V, 1.6-V, 1.8-V, 2.5-V Fixed-Output and Adjustable Versions (1.2-V to 5.5-V)
• Input Voltage Down to 1.8 V
• Low 170-mV Dropout Voltage at 1 A (TPS72525)
• Stable With Any Type/Value Output Capacitor
• Integrated Supervisor (SVS) With 50-ms RESET Delay Time
• Low 210-µA Ground Current at Full Load (TPS72525)
• Less than 1-µA Standby Current
Plasma TV Service Manual
25
11/01/2005
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