MICRF008BM TR Micrel Inc, MICRF008BM TR Datasheet - Page 8

• Manufacturer Part Number: MICRF008BM TR
• Manufacturer: Micrel Inc

Specifications of MICRF008BM TR

• Operating Band Frequency: 300 to 440MHz
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Product Depth (mm): 3.94mm
• Product Height (mm): 1.48mm
• Operating Supply Voltage (min): 4.75V
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Lead Free Status / Rohs Status: Not Compliant

REFOSC Pin
The REFOSC input circuit is shown in Figure 5. Input
impedance is quite 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 VSSBB. The resonators
should not contain integral capacitors, since these
capacitors are contained inside the IC. Externally applied
signals should be AC-coupled, amplitude limited to
approximately 0.5V
this pin is 1.4V.
Micrel, Inc.
August 2008
REFOSC
Compa-
rator
Figure 5. REFOSC Pin
PP
30pF
30pF
Figure 4. DO Pin
. The nominal DC bias voltage on
VSSBB
Active
Bias
250
200k
VDDBB
VSSBB
15µA
VDDBB
10µA
10µA
VSSBB
DO
8
Control Input (SEL0)
Control input circuitry is shown in Figure 6. 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 VDDBB. Typical pullup
current is 5μA, leading to an impedance to the VDDBB
supply of typically 1MΩ.
Logic
Input
VSSBB
VDDBB
Figure 6. SEL0
Q1
VSSBB
Q2
Q3
to Interna
Circuits
M9999-080108
MICRF008