nRF24E2 Nordic VLSI, nRF24E2 Datasheet - Page 11

• Manufacturer Part Number: nRF24E2
• Description: Single Chip RF Transmitter + MCU + ADC NRF2402 2.4GHz RF Transmitter
• Manufacturer: Nordic VLSI

PRODUCT SPECIFICATION
Most of the GPIO pins can be used for multiple purposes under program control. The
alternate functions include two external interrupts, UART RXD and TXD, a SPI
master port, three enable/count signals for the timers and the PWM output.
The nRF24E2 can be set into a low power down mode under program control, and
also the ADC and RF subsystems can be turned on or off under program control. The
CPU will stop, but all RAM’s and registers maintain their values. The low power RC
oscillator is running, and so are the watchdog and the RTC wakeup timer (if enabled
by software). The current consumption in this mode is typically 2µA.
The device can exit the power down mode by an external pin interrupt (INT0_N or
INT1_N) if enabled, by the wakeup timer if enabled or by a watchdog reset.
The nRF24E2 contains a low power RC oscillator which can not be disabled, so it will
run continuously as long as VDD
RTC Wakeup Timer and Watchdog are two 16 bit programmable timers that run on
the RC oscillator LP_OSC clock. The resolution of the watchdog and wakeup timer is
programmable from approximately 300µs to approximately 80ms. By default the
resolution is 10ms. The wakeup timer can be started and stopped by user software.
The watchdog is disabled after a reset, but if activated it can not be disabled again,
except by another reset
Both the microcontroller, ADC and RF front end run on a crystal oscillator generated
clock. A range of crystals frequencies from 4 to 20 MHz may be utilised, but 16 MHz
is recommended since it gives best over all performance. For details, please see
Crystal Specification on page 85. The oscillator may be started and stopped as
requested by software.
The nRF24E2 AD converter has 10 bit dynamic range and linearity with a conversion
time of 48 CPU instruction cycles per 10-bit result.
The reference for the AD converter is software selectable between the AREF input
and an internal 1.22V bandgap reference.
The converter has 9 inputs selectable by software. Selecting one of the inputs 0 to 7
will convert the voltage on the respective AIN0 to AIN7 pin.
Input 8 enables software to monitor the nRF24E2 supply voltage by converting an
internal input that is VDD/3 with the 1.22V internal reference selected.
The AD converter is typically used in a start/stop mode. The sampling time is then
under software control.
Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone [phone] - Fax [phone]
Revision: 1.0
August 2003
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