ROHM BH4126FV Datasheet

BH4126FV

Communication ICs

Wide band IF detector for RF remote
control units

BH4126FV

The BH4126FV is an IC equipped with internal mixer, IF amplifier, and FM detector circuits, developed for use with RF
remote control units.

Applications

!

Keyless entry

Features

!

1) Equipped with internal mixer, IF, RSSI, and FM
detection circuits.

2) Can be operated at mixer input frequencies ranging
from 20MHz to 300MHz.

3) Equipped with a battery power saving function.

4) Fast RSSI response.

5) High FM detection sensitivity. (21.2mV / kHz)

Communication ICs

Block diagram

!!!!

IF input

FM detector

output

IF output

RSSI

BH4126FV

V

CC

16 15

Local OSC.

1

Local

14

Battery save

13 12 11 10

Quadrature

DET.

9

V

CC

RSSI

IF

V

CC

8765432

V

CC

Absolute maximum ratings

!!!!

Parameter Symbol
Power supply voltage V
Power dissipation P

(Ta=25°C, for measurement circuit)

Limits

CC

D

7.0 V

*1

350

Storage temperature Tstg -55~+125 ˚C

*1 Reduced by 3.5 mW for each increase in Ta of 1˚C over 25˚C.

Operating range

!!!!

Parameter Symbol
Operating power supply voltage

V

CC

Operating temperature Topr

Limits

2.3~5.5 V

-40~+85

Unit

mW

Unit

˚C

Communication ICs

Pin descriptions

!!!!

Pin No.

BH4126FV

Function DC voltage(V)Internal peripheral circuit

Local oscillator pin (base)
Connect crystal resonator

and capacitor

1

Local oscillator pin (emitter)

Connect capacitor or input local signal

2

from external oscillator

Battery save pin
"Pin 3 voltage" ≤ 0.2 : Battery save
2 V ≤ "Pin 3 voltage" ≤ V

3

Mixer output pin
Connect ceramic filter
Output impedance: 330Ω

CC

: Active

V

CC

V

CC

-

0.6

5k

1

2

30k

3

To MIXER

CC

V

-

V

CC

4

4

270

GND pin GND for IF stages and FM detection stages

5

V

CC

-

GND

1.5