MAX2745 View Datasheet(PDF) - Maxim Integrated

Part Name

Description

Manufacturer

MAX2745

Single-Chip Global Positioning System Receiver Front-End

Maxim Integrated 

Single-Chip Global Positioning System

Receiver Front-End

Typical Operating Characteristics (continued)

(MAX2745 EV kit, VDD = +3.0V, SHDN = GND, fRF = 1575.42MHz, and TA = +25°C, unless otherwise noted.)

TOTAL GAIN vs. TEMPERATURE

110

VCC = 3V

108

VCC = 2.7V

106

104

VCC = 2.4V

102

TEMPERATURE-SENSOR OUTPUT VOLTAGE

vs. TEMPERATURE

1.6

1.4

1.2

1.0

VDD = 3.6V

0.8

0.6

0.4

VDD = 2.4V

0.2

VOLTAGE-BOOSTER

OUTPUT vs. VDD_VB

3.2

BST_CTRL = HIGH

VOUT = VDD

3.0

TA = -40°C

2.8

2.6

TA = +25°C

2.4

TA = +85°C

2.2

100

-40 -20 0 20 40 60 80

TEMPERATURE (°C)

0

-40 -20 0 20 40 60 80

TEMPERATURE (°C)

2.0

1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3

VDD_VB (V)

Pin Description

PIN

1

2

3, 4, 9, 11, 13,

25, 27, 32, 39,

43, 46

NAME

RBIAS

CBIAS

VDD

FUNCTION

External BIAS Resistor. For normal bias, connect a 100kΩ (1%) resistor to ground.

BIAS Bypass Capacitor. Connect a 0.1µF capacitor to ground.

Power-Supply Voltage. Bypass with a 0.1µF capacitor to ground as close to the pins as possible.

5, 6, 8, 14, 26,

30, 41, 44

GND

Ground

7

RFIN

RF Input Signal. Requires external matching network.

10

IEXT_LNA External LNA Voltage Supply

12

AGC_FIL AGC External Filter. Requires external RC lowpass filter.

15

XTAL_SSEL Crystal Swing Select. Drive logic high for full swing. Drive logic low for limited swing.

16

XTAL_CSEL

Crystal Clock Select. Drive logic high for fundamental mode of 16.368MHz. Drive logic low for third

overtone mode of 32.736MHz.

17

BST_CTRL Active-High Boost Control Input. Drive logic high to activate the voltage booster (crystal oscillator is

biased from BIAS). Drive logic low to deactivate the voltage booster (crystal oscillator is self-biased).

18

TEST_EN Connect to Ground for Normal Operation

19

VDD_VB Power Supply for Voltage Booster. Connect to VDD if voltage booster is not used.

20

CKOUT Full-Swing Clock Output

21

DOUT Single-Ended Full-Swing Digital Output

22

VB_CS+ Positive Voltage Booster External Floating CAP. Connect a 6nF capacitor to GND.

23

VB_CS- Negative Voltage Booster External Floating CAP. Connect a 6nF capacitor to GND.

24

VOUT

Voltage Booster Output. Bypass to GND with a 1µF capacitor as close to the pin as possible.

4 _______________________________________________________________________________________

Share Link: