SX1242, Rev 1, November 2010

©2010 Semtech Corp.

SX1242

www.semtech.com

Page 6

Integrated Transmitter IC

ADVANCED COMMUNICATIONS & SENSING

DATASHEET

2.4. Electrical Specifications

The table below gives the electrical specifications of the transmitter under the following conditions: Supply voltage = 3.3 V,

matched 50 ohm impedance, unless otherwise specified.

Table 4

Transmitter Specifications

*

Logic “1” transmission indicated by transmission of carrier frequency at power level RFOP.

**

Ramp-up time of the internal regulator turning the PA on. The typical 10% - 90% power ramp-up time is 10us

Symbol

Description

Conditions

Min

Typ

Max

Unit

Current Consumption

IDDSL

Supply current in sleep mode

-

0.5

1

µA

IDDT

Supply current in transmit mode

with appropriate external match-

ing.

Logic “1” or “Mark” frequency trans-

mitted*

-22-

mA

RF and Baseband Specifications

BRO

Bit rate, OOK

Permissible range

0.5

-

10

kbps

OOK_B

OOK modulation depth

-

50

-

dB

RFOP

RF output power into 50 ohms

Optimized matching network

9

12

-

dBm

DRFOPV

Variation in RF output power with

supply voltage

2.5 V to 3.3 V

1.8 V to 3.7 V

-

-

-

-

3

7

dB

dB

PHN

Transmitter phase noise

100 kHz Offset from carrier

-

-

-76

dBc/Hz

FCN

Carrier frequency

-

344.94

-

MHz

FXOSC

Crystal Oscillator Frequency

26

26

26

MHz

DFXOSC

Frequency Variation of the Oscilla-

tor Circuit

No crystal contribution

-

-

+/-25

ppm

Timing Specifications

TS_TR

Time from Sleep to Tx mode

-

-

2

ms

RAMP

PA Ramp up and down time**

-

20

-

us