Datasheet
Table Of Contents
- FEATURES
- APPLICATIONS
- DESCRIPTION
- ABSOLUTE MAXIMUM RATINGSsecond and third footnotes to Absolute Maximum Ratings table.
- RECOMMENDED OPERATING CONDITIONS
- ELECTRICAL CHARACTERISTICS
- DIGITAL CHARACTERISTICS
- TIMING CHARACTERISTICSrows 5 through 15, and footnotes 5 and 6 to Timing Characteristics table.
- RESET TIMING CHARACTERISTICS
- SERIAL PROGRAMMING INTERFACE CHARACTERISTICS
- PIN CONFIGURATION
- DEFINITION OF SPECIFICATIONSthe Definition of Specifications section.
- TYPICAL CHARACTERISTICS
- TYPICAL CHARACTERISTICS
- APPLICATION INFORMATIONInput Voltage Stress section in Applications Information.
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R
F
R
G
V
OCM
INP
INM
CM
R
F
R
G
R
S
0.1
µ
F
0.1
µ
F
10
µ
F
1
µ
F
R
T
+3.3V
+5V
0.1
µ
F10
µ
F
−
5V
THS4503
R
IN
R
IN
10
Ω
ADS5541
14-Bit / 105MSPS
POWER-SUPPLY SEQUENCE
REFERENCE CIRCUIT
AV
DD
REFP
29
28
2kΩ
1Ω
1µF
POWER-DOWN
29
30
31
REFP
REFM
IREF
1Ω
1Ω
56kΩ
1µF
1µF
Production Data
ADS5541
SBAS307C – MAY 2004 – REVISED FEBRUARY 2007
Figure 42. Using the THS4503 with the ADS5520
Using the serial interface PDN bit to power down the
device places the outputs in a high-impedance state
and only the internal reference remains on to reduce
The preferred mode of power-supply sequencing is
the power-up time. The power-down mode reduces
to power up AV
DD
first, followed by DRV
DD
. Raising
power dissipation to approximately 180mW.
both supplies simultaneously is also a valid
power-supply sequence. In the event that DRV
DD
powers up before AV
DD
in the system, AV
DD
must
power up within 10ms of DRV
DD
. Optionally, it is
The ADS5541 has built-in internal reference
recommended to put a 2k Ω resistor from REFP (pin
generation, requiring no external circuitry on the
29) to AV
DD
as shown in Figure 43 . This
printed circuit board (PCB). For optimum
configuration helps to make the device more robust
performance, it is best to connect both REFP and
to power supply ramp-up timings.
REFM to ground with a 1 µ F decoupling capacitor
(the 1 Ω resistor shown in Figure 44 is optional). In
addition, an external 56k Ω resistor should be
connected from IREF (pin 31) to AGND to set the
proper current for the operation of the ADC, as
shown in Figure 44 . No capacitor should be
connected between pin 31 and ground; only the
56k Ω resistor should be used.
Figure 43.
The device enters power-down in one of two ways:
either by reducing the clock speed or by setting the
PDN bit via the serial programming interface. Using
the reduced clock speed, power-down may be
initiated for clock frequency below 2MSPS. The
exact frequency at which the power-down occurs
varies from device to device.
Figure 44. REFP, REFM, and IREF Connections
for Optimum Performance
24
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