MRF49XA-I/ST Microchip Technology, MRF49XA-I/ST Datasheet - Page 46

• Manufacturer Part Number: MRF49XA-I/ST
• Description: IC RF TXRX 433/868/915 16-TSSOP
• Manufacturer: Microchip Technology

Specifications of MRF49XA-I/ST

• Package / Case: 16-TSSOP
• Frequency: 433MHz, 868MHz, 915MHz
• Data Rate - Maximum: 256kbps
• Modulation Or Protocol: FHSS, FSK
• Applications: Home / Industrial Automation, Remote Access, Security Alarms
• Power - Output: 7dbm
• Sensitivity: -110dBm
• Voltage - Supply: 2.2 V ~ 3.8 V
• Current - Receiving: 11mA
• Current - Transmitting: 15mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Number Of Receivers: 1
• Number Of Transmitters: 2
• Wireless Frequency: 433 MHz to 915 MHz
• Output Power: + 7 dBm
• Operating Supply Voltage: 2.5 V, 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Modulation: FHSS, FSK
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Memory Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 579-MRF49XA-1/ST

3.1.2
Spikes or glitches are found on the V
supply filtering is not satisfactory, or the internal resis-
tance of the power supply is very high. So, in this case,
the Sensitive Reset mode needs to be enabled. Here,
the device Reset occurs due to the transients present
on the V
The internal Reset block has two basic modes of
operation:
• Sensitive Reset Mode
• Normal Reset Mode
Sensitive Reset Mode: By enabling the Sensitive
Reset, a Reset is generated if:
• the positive going edge of the V
• the voltage difference between the internal ramp
The Sensitive Reset mode is the default mode which
can be changed by using the DRSTM bit (FIFOR-
STREG<0>). Figure 3-2 shows the Sensitive Reset
mode.
FIGURE 3-2:
DS70590B-page 44
MRF49XA
rate greater than 100 mV/ms, and
signal and the V
voltage (600 mV).
(Pin 10)
RESET
Output
DD
line.
POWER GLITCH RESET
1.6V
V
H
L
DD
DD
reaches the Reset threshold
SENSITIVE RESET ENABLED
DD
DD
has a rising
line if the power
Voltage (600 m V)
Reset Threshold
Preliminary
Normal Reset Mode: The device enters this mode,
when the power glitch detection circuit is disabled.
Figure 3-3 shows the Normal Reset mode.
If the Sensitive mode is disabled and the power supply
is turned off, the V
Power-on Reset when the supply voltage is reapplied.
If the decoupling capacitors retain their charges for a
longer duration, there might be no Reset after
power-up as the power glitch detector is disabled.
Note:
Note:
Negative change in the supply voltage
does not cause a Reset event unless the
V
voltage (i.e., 250 mV in Normal Reset
mode, 1.6V in Sensitive Reset mode).
The Reset event reinitializes the internal
registers, and thus, the Sensitive mode is
enabled again.
DD
level reaches the Reset threshold
DD
© 2009 Microchip Technology Inc.
requires 250 mV to trigger a
Reset Ram p Line
(100 m V/m s)
Tim e