MICRF033BM Micrel Inc, MICRF033BM Datasheet - Page 3

• Manufacturer Part Number: MICRF033BM
• Manufacturer: Micrel Inc

Specifications of MICRF033BM

• Lead Free Status / Rohs Status: Not Compliant

October 1999
MICRF003
Pin Description (Pin numbers for the 8-pin version are identified in parentheses)
Pin Number
SEL0
2/3
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
10
11
12
13
14
15
16
1
4
5
6
7
8
9
1
0
1
0
Pin Name
REFOSC
WAKEB
VDDRF
VDDBB
VDDRF
VSSRF
VSSRF
VSSBB
SWEN
CAGC
SHUT
SEL0
SEL1
ANT
CTH
N/C
DO
SEL1
1
1
0
0
Pin Function
This pin, in conjunction with SEL1, programs the desired Demodulator Filter Bandwidth. This pin is internally
pulled-up to VDDRF. See Table 1.
This pin is the ground return for the RF section of the IC. The bypass capacitor connected from VDDRF to
VSSRF should have the shortest possible lead length. For best performance, connect VSSRF to VSSBB at the
power supply only (i.e., keep VSSBB currents from flowing through VSSRF return path).
This pin is the ground return for the IC. The bypass capacitor connected from VDDRF to VSSRF should have
the shortest possible lead length.
This is the receive RF input, internally ac-coupled. Connect this pin to the receive antenna. Input impedance is
high (FET gate) with approximately 2pF of shunt (parasitic) capacitance. For applications located in high
ambient noise environments, a fixed value band-pass network may be connected between the ANT pin and
VSSRF to provide additional receive selectivity and input overload protection. (See “Application Note TBD”.)
This pin is the positive supply input for the RF section of the IC. VDDBB and VDDRF should be connected
directly at the IC pins. Connect a low ESL, low ESR decoupling capacitor from this pin to VSSRF, as short as
possible.
This pin is the positive supply input for the baseband section of the IC. VDDBB and VDDRF should be
connected directly at the IC pins.
This pin is the positive supply input for the IC. Connect a low ESL, low ESR decoupling capacitor from this pin
to VSSRF, as short as possible.
This capacitor extracts the (DC) average value from the demodulated waveform, which becomes the reference
for the internal data slicing comparator. Treat this as a low-pass RC filter with source impedance of nominally
90kohms ( for REFOSC frequency Ft = 6.75MHz, see “Application Note TBD”). A standard
ceramic capacitor is generally sufficient.
Unused Pin
This is the ground return for the baseband section of the IC. The bypass and output capacitors connected to
VSSBB should have the shortest possible lead lengths. For best performance, connect VSSRF to VSSBB at
the power supply only (i.e., keep VSSBB currents from flowing through VSSRF return path).
The output data signal. CMOS level compatible.
A logic input for Shutdown Mode control. Pull this pin low to place the IC into operation. This pin in internally
pulled-up to VDDRF.
An output signal, active low when the IC detects an incoming RF signal, determined by monitoring for data
preamble. CMOS level compatible.
Integrating capacitor for on-chip AGC (Automatic Gain Control). The Decay/Attack time-constant (TC) ratio is
nominally set as 10:1. Use of 0.47uF or greater is strongly recommended for best range performance. Use
low-leakage type capacitors for duty-cycle operation (Dip Tantalum, Ceramic, Polyester). (See “Application Note
TBD.)
This pin, in conjunction with SEL0, programs the desired Demodulator Filter Bandwidth. This pin in internally
pulled-up to VDDRF. See Table 1.
This is the timing reference for on-chip tuning and alignment. Connect either a ceramic resonator or crystal
(mode dependent) between this pin and VSSBB, or drive the input with an AC coupled 0.5Vpp input clock. Use
ceramic resonators without integral capacitors. Note that if operating in FIXED mode, a crystal must be used;
however in SWP mode, one may use either a crystal or ceramic resonator. See “Application Note TBD” for
details on frequency selection and accuracy.
This logic pin controls the operating mode of the MICRF003. When SWEN = HIGH, the MICRF003 is in SWP
mode. When SWEN = LOW, the device operates as a conventional single-conversion superheterodyne
receiver. (See “Application Note TBD” for details.) This pin is internally pulled-up to VDDRF.
Nominal Demodulator (Baseband) Filter Bandwidth
vs. SEL0, SEL1 and Mode
SWP Mode
3000
1500
6000
750
QwikRadio
Table 1
3
Demodulator Bandwidth (Hz)
tm
FIXED Mode
22400
11200
2800
5600
20% X7R
MICRF003
Micrel