MAX1359B Maxim Integrated Products, MAX1359B Datasheet - Page 29

• Manufacturer Part Number: MAX1359B
• Description: Data-Acquisition System
• Manufacturer: Maxim Integrated Products

DataSheet.in
An internal oscillator and a frequency-locked loop (FLL)
are used to generate a 4.9152MHz ±1% high-frequen-
cy clock. This clock and derivatives are used internally
by the ADC, analog switches, and PWM. This clock sig-
nal outputs to CLK. When the FLL is enabled, the high-
frequency clock is locked to the 32.768kHz reference.
If the FLL is disabled, the high-frequency clock is free-
running. At power-up, the CLK pin defaults to a
2.4576MHz clock output, which is compatible with most
µCs. See Figure 12 for a block diagram of the high-fre-
quency clock.
The MAX1359B provides four digital programmable
I/Os (UPIO1–UPIO4). Configure UPIOs as logic inputs
or outputs using the UPIO control register. Configure
the internal pullups using the UPIO setup register, if
Figure 11. Watchdog Timer Block Diagram
Figure 12. High-Frequency Clock and FLL Block Diagram
UPIOs, RTC, Voltage Monitors, and Temp Sensor
16-Bit, Data-Acquisition System with ADC, DAC,
M32K
32K
______________________________________________________________________________________
POR PULSES HIGH DURING POWER-UP.
WDW PULSES HIGH DURING WATCHDOG REGISTER WRITE.
FLLE
WDE
FREQUENCY
User-Programmable I/Os
COMPARE
High-Frequency Clock
ERROR
FREQ
BY-8192
DIVIDE-
WDW
POR
32.768kHz
INTEGRATOR
FREQUENCY
4Hz
TUNE<8:0>
D
CK
R
Q
Q
CONTROLLED
OSCILLATOR
DIGITALLY
HFCE
required. At power-up, the UPIO’s are internally pulled
up to DV
or CPOUT. See the UPIO__CTRL Register and
UPIO_SPI Register sections for more details on config-
uring the UPIO_ pins.
Program each UPIO1–UPIO4 as one of the following:
• General-purpose input
• Power-mode control
• Analog switch (SPST) and SPDT control input
• ADC data-ready output
• General-purpose output
• PWM output
• Alarm output
• SPI passthrough
DD
CKSEL2
0
1
MUX
2:1
. UPIO_ outputs can be referenced to DV
CK
D
4.9152MHz HF OSCILLATOR AND FLL
R
Q
Q
CKSEL<1:0>
4.9152MHz
1, 2, 4, 8
DIVIDER
WATCHDOG TIMER
CLKE
WDTO
HFCLK
CRDY
CLK
DD
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