MICRF002BM Micrel Inc, MICRF002BM Datasheet - Page 13

• Manufacturer Part Number: MICRF002BM
• Description: IC ASK RCVR RF/IF SHUTDWN 16SOIC
• Manufacturer: Micrel Inc

Specifications of MICRF002BM

• Frequency: 300MHz ~ 440MHz
• Sensitivity: -95dBm
• Data Rate - Maximum: 10 kbps
• Modulation Or Protocol: ASK, OOK
• Applications: RKE
• Current - Receiving: 2.2mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Features: Automatic Tuning
• Voltage - Supply: 4.75 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 16-SOIC (0.154", 3.90mm Width)
• No. Of Driver/receivers: 0/1
• Peak Reflow Compatible (260 C): No
• Current Rating: 0.01A
• Supply Voltage Max: 5.5V
• Data Rate Max: 10Kbps
• Leaded Process Compatible: No
• Mounting Type: Surface Mount
• Supply Current: 2.4mA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Memory Size: -
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant, Contains lead / RoHS non-compliant

C
Figure 3 illustrates the C
control voltage is developed as an integrated current into a
capacitor C
the decay current is a 1/10th scaling of this, nominally
1.5µA, making the attack/decay time constant ratio a fixed
10:1. Signal gain of the RF/IF strip inside the IC diminishes
as the voltage at C
attack/decay ratio is possible by adding resistance from the
C
Both the push and pull current sources are disabled during
shutdown, which maintains the voltage across C
improves recovery time in duty-cycled applications. To
further improve duty-cycle recovery, both push and pull
currents are increased by 45 times for approximately 10ms
after release of the SHUT pin. This allows rapid recovery of
any voltage droop on C
DO and WAKEB Pins
The output stage for DO (digital output) and WAKEB
(wakeup output) is shown in Figure 4. The output is a 10µA
push and 10µA pull switched-current stage. This output
stage is capable of driving CMOS loads. An external buffer-
Micrel, Inc.
July 2008
AGC
AGC
pin to either V
Pin
Timout
AGC
Compa-
rator
Figure 4. DO and WAKEB Pins
. The attack current is nominally 15µA, while
DDBB
Compa-
rator
Figure 3. CAGC Pin
1.5µA
AGC
15µA
AGC
or V
AGC
decreases. Modification of the
while in shutdown.
SSBB
VDDBB
VSSBB
pin interface circuit. The AGC
, as desired.
VDDBB
VSSBB
67.5µA
675µA
10µA
10µA
DO
CAGC
AGC
, and
13
driver is recommended for driving high-capacitance loads.
REFOSC Pin
The REFOSC input circuit is shown in Figure 5. Input
impedance is high (200kΩ). This is a Colpitts oscillator with
internal 30pF capacitors. This input is intended to work with
standard ceramic resonators connected from this pin to the
V
frequency accuracy is required. The nominal dc bias
voltage on this pin is 1.4V.
SEL0, SEL1, SWEN, and SHUT Pins
Control input circuitry is shown in Figures 6a and 6b. The
standard input is a logic inverter constructed with minimum
geometry MOSFETs (Q2, Q3). P-channel MOSFET Q1 is
a large channel length device which functions essentially
as a “weak” pullup to V
leading to an impedance to the V
1MΩ.
SSBB
pin, although a crystal may be used when greater
Figure 6a. SEL0, SEL1, SWEN Pins
SWEN
SHUT
SHUT
SEL0,
SEL1,
REFOSC
Figure 5. REFOSC Pin
VSSBB
VSSBB
Figure 6b. SHUT Pin
30pF
30pF
VDDBB
VDDBB
DDBB
VSSBB
Q1
Q1
Q4
. Typical pull-up current is 5µA,
Active
Bias
250
VSSBB
VSSBB
200k
Q2
Q3
Q2
Q3
30µA
DDBB
to Internal
Circuits
to Internal
Circuits
VDDBB
VSSBB
MICRF002/RF022
supply of typically
M9999-070808