MAXIM MAX2165 Technical data

General Description

The MAX2165 direct-conversion tuner IC is designed for
handheld digital video broadcast (DVB-H) applications.
The tuner covers a 470MHz to 780MHz input frequency
range and features an I/Q baseband interface.

The MAX2165’s direct-conversion architecture elimi­nates the need for an IF-SAW filter, allowing for
reduced bill of materials cost. The design integrates a
variable-gain, low-noise amplifier (LNA); a notch filter;
an RF tracking filter; a quadrature mixer; a power
detector; programmable baseband lowpass channel­selection filters; baseband variable-gain amplifiers
(VGA); DC offset correction circuitry; and a complete
fractional-N frequency synthesizer. The part is program­mable through a 2-wire I2C-compatible serial interface.

The MAX2165 integrates a tuneable notch filter. This fil­ter is designed to notch out interfering signals in the
830MHz to 950MHz frequency range to allow for opera­tion in the presence of large cellular signals.
Programmable baseband channel-selection filters allow
for operation with 7MHz and 8MHz channels. Digital DC
offset correction circuitry supports time-sliced operation
by minimizing power-up time delay. The fractional-N
synthesizer reduces VCO lock time and minimizes
close-in phase noise, eliminating the need for power­hungry, phase-noise reduction algorithms.

The MAX2165 is available in a tiny, 5mm x 5mm x

0.8mm, 28-pin thin QFN package with an exposed pad­dle. It is specified for operation over the -40°C to +85°C
extended temperature range.

Applications

DVB-H Handheld Receivers

DVB-T Portable Devices

DMB-T/H Portable Devices

ISDB-T Receivers (13 Segment)

Features

o 93mA (typ) Current Consumption from a Single

+2.85V Supply Voltage

o 21mW (typ) Average Power Consumption at 8%

Duty Cycle

o Direct-Conversion Architecture Eliminates IF-

SAW Filter

o Integrated RF Tuneable Notch Filter for Operation

in the Presence of Cellular Blockers

o Integrated DC Offset Correction Circuitry
o Integrated RF Notch Filter for Operation in the

Presence of Up to -7dBm Cellular Blockers

o Extended UHF Band Operation
o 5mm x 5mm x 0.8mm, 28-Pin Thin QFN Package

MAX2165

Single-Conversion DVB-H Tuner

________________________________________________________________

Maxim Integrated Products

1

Pin Configuration/

Functional Diagram

Ordering Information

19-0646; Rev 1; 3/09

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.

+

Denotes a lead(Pb)-free/RoHS-compliant package.

*

EP = Exposed paddle.

EVALUATION KIT

AVAILABLE

PART TEMP RANGE PIN-PACKAGE

MAX2165ETI+ -40°C to +85°C 28 TQFN-EP*

XB

VCC_XTAL

REFOUT

MUX

VCC_SYN

SDA

SCL

N.C.

RFIN

ADDR

VCC_RF

LEXT

XE

28 27 26 25 24 23 22

+

1

SERIAL INTERFACE, CONTROL,

2

3

4

5

6

7

AND SYNTHESIZER

MAX2165

TO

CONTROL

BLOCK

DAC

EP

0°

90°

PWRDET

CHARGE

PUMP

CP

21

LDO

20

GND_TUNE

19

VTUNE

18

VCC_VCO

17

BB_AGC

16

BBI+

15

BBI-

8 9 10 11 12 13 14

STBY

SHDN

RF_AGC

THIN QFN

5mm x 5mm

OVLD_DET

VCC_BB

BBQ-

BBQ+

MAX2165

Single-Conversion DVB-H Tuner

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(MAX2165 EV kit, VCC= +2.75V to +3.3V, V

RF_AGC

= V

BB_AGC

= 2.3V (maximum gain), no RF input signals at RFIN, default register set-

tings, T

A

= -40°C to +85°C, unless otherwise noted. Typical values are at VCC= +2.85V, TA= +25°C, unless otherwise noted.) (Note 1)

AC ELECTRICAL CHARACTERISTICS

(MAX2165 EV kit, VCC= +2.75V to +3.3V, V

RF_AGC

= V

BB_AGC

= 2.3V (maximum gain), V

OUT

= 1V

P-P

, 75Ω system impedance, reg-

isters set according to the specified default register conditions, T

A

= -40°C to +85°C, unless otherwise noted. Typical values are at

V

CC

= +2.85V, TA= +25°C, unless otherwise noted.) (Note 1)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

All VCCPins to GND ..............................................-0.3V to +3.6V

GND_TUNE to GND ..............................................-0.3V to +0.3V

All Other Pins to GND.................................-0.3V to (V

CC

+ 0.3V)

BBI_, BBQ_ Short Circuit to Ground Duration ...............Indefinite

Maximum RF Input Power ..............................................+13dBm

Continuous Power Dissipation (T

A

= +70°C)

28-Pin Thin QFN (derate 34.5mW/°C above +70°C).....2758mW

Operating Temperature Range ...........................-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

CAUTION! ESD SENSITIVE DEVICE

PARAMETER CONDITIONS MIN TYP MAX UNITS

SUPPL Y VOLTAGE AND CURRENT

Supply Voltage 2.75 3.30 V

Supply Current

Shutdown Current 20 µA

Gain-Control Voltage Required to obtain full range of RF and baseband gain 0.4 2.3 V

RF_AGC and BB _AGC Input
Bias Current

SERIAL INTERFACE

Input Logic-Leve l Low

Input Logic-Leve l High

Input Hysteres is

SDA, SCL Input Current -10 +10 µA

Output Logic-Leve l Low I

Output Logic-Leve l H igh I

LNASW = 1 (RF LNA on) 109 134

LNASW = 0 (RF LNA off) 93 116

V

AGC

SINK

SOURCE

at +0.4V and +2.3V -50 +50 µA

= 0.3mA 0.4 V

= 0.3mA

0.3 x
V

CC

0.7 x
V

CC

V

CC

0.4

-

V

0.05 x
V

CC

V

V

mA

V

OVERALL PERFORMANCE (RF INPUT TO BASEBAND OUTPUTS)

Operating Frequency Range

Input Return Loss

PARAMETER CONDITIONS MIN TYP MAX UNITS

Meets specified performance 470 783

Operates with derated performance (Note 2) 470 832

50Ω system, w or st case acr oss b and , any g ai n- contr ol
setti ng ( N ote 3)

7dB

MHz

MAX2165

Single-Conversion DVB-H Tuner

_______________________________________________________________________________________ 3

AC ELECTRICAL CHARACTERISTICS (continued)

(MAX2165 EV kit, VCC= +2.75V to +3.3V, V

RF_AGC

= V

BB_AGC

= 2.3V (maximum gain), V

OUT

= 1V

P-P

, 75Ω system impedance, reg-

isters set according to the specified default register conditions, T

A

= -40°C to +85°C, unless otherwise noted. Typical values are at

V

CC

= +2.85V, TA= +25°C, unless otherwise noted.) (Note 1)

Voltage Gain

RF Gain-Control Range 0.4V ≤ V

Baseband Gain-Control Range 0.4V ≤ V

LNA Gain Step

LNA Gain Step Phase Change

Noise Figure (Note 3)

Input IP2 (Note 4)

Input IP3 (Note 5)

In-Band Input P

Cellular Blocker Desensitization
(Note 7)

In-Band IM3

RF Beats Converted to Output

RF Isolation

I/Q Output Swing Z

I/Q DC Voltage I+, I-, Q+, Q- outputs to ground VCC / 2 V

I/Q Quadrature Accuracy

Spurious Emissions at RF Input
(Note 3)

Closed-Loop Phase Noise

PARAMETER CONDITIONS MIN TYP MAX UNITS

1dB

Z

SOURCE

1kΩ

Gain change caused by switching RF LNA on (LNASW =

1) and off (LNASW = 0)

Phase change caused by switching RF LNA on (LNASW
= 1) and off (LNASW = 0)

At 470MHz 3.8 6.5

At 783MHz 4.0 6.5

Maximum gain 0 9

23dB gain reduction 26

Maximum gain -20 -4

23dB gain reduction 17

Maximum gain (Note 6)

Cellular Tx blocker gain compression 1.2 3

Cellular Tx blocker noise figure rise 3

Two tones (782.8MHz and 782.3MHz) within passband of
baseband filter, 780MHz LO frequency

170MHz to 960MHz RF input frequency < -60

960MHz to 1400MHz RF input frequency < -60

DC to 50MHz, RF input to baseband outputs relative to
desired channel

= 10kΩ || 10pF 0.5 1 V

LOAD

Phase error 2 degrees

Amplitude error -1.5 +1.5 dB

50MHz to 470MHz -38 -33

470MHz to 878MHz -52 -35

878MHz to 1732MHz -49 -35

Spur at four times Rx frequency, tested at f

= 1896MHz

f

SPUR

1kHz offset to 10kHz (Note 3) -86 -96

1MHz offset (Note 3) -108 -126

> 10MHz offset -140

= 75Ω, Z

≤ 2.3V 29

RF_AGC

≤ 2.3V 21 25 dB

BB_AGC

Maximum gain 74 82

>

LOAD

Minimum gain on
(LNASW = 1)

= 474MHz,

LO

23 29

34

13.5 17 dB

10 degrees

-22 dBm

-55 -40 dBc

-60 dBc

-58 -51 dBm

dB

dB

dB

dBm

dBm

dB

dBc

P-P

dBmV

dBc/Hz

MAX2165

Single-Conversion DVB-H Tuner

4 _______________________________________________________________________________________

AC ELECTRICAL CHARACTERISTICS (continued)

(MAX2165 EV kit, VCC= +2.75V to +3.3V, V

RF_AGC

= V

BB_AGC

= 2.3V (maximum gain), V

OUT

= 1V

P-P

, 75Ω system impedance, reg-

isters set according to the specified default register conditions, T

A

= -40°C to +85°C, unless otherwise noted. Typical values are at

V

CC

= +2.85V, TA= +25°C, unless otherwise noted.) (Note 1)

Power-Up Time

BASEBAND FILTERS

PARAMETER CONDITIONS MIN TYP MAX UNITS

Shutdown to full operation, VCO settled to the Rx
frequency, DC offset calibrated (Note 8)

Lower corner (Note 9)

Passband Cutoff Attenuation

Amplitude Ripple TA = +25°C 0.5 1.5 dB

Group Delay Ripple 150 µs

Group Delay Matching 5ns

Rejection Ratio (Note 10)

FRACTIONAL SYNTHESIZER

RF N-Divider Ratio 7 251

RF R-Divider Ratio 12

Fractional Ratio Length of fractional accumulator (Note 13) 20 bits

Integer Spurs Worst-case spur inside baseband filter bandwidth -60 dBc

Settling Time

Charge-Pump Current

Charge-Pump Leakage -10 +10 µA

REFERENCE OSCILLATOR

Reference Frequency 4 26 MHz

Reference Buffer Output Voltage
Swing

Input Impedance

Input Voltage

OVERLOAD DETECTOR

Attack-Point Accuracy ±2.5 dB

Attack-Point Increment 3-bit DAC, change per LSB step 2.5 dB

Detector Output Sink

Upper corner at 3.85MHz (UHF mode), TA = +25°C 0.9 5

Upper corner at 3.35MHz (VHF mode), T

4.75MHz (VHF mode) (Note 11) 23

5.25MHz (UHF mode) (Note 11) 23

14.5MHz (VHF and UHF mode) (Note 12) 59 75

> 16.2MHz 84

35MHz step, settled to within 100Hz frequency error / 20°
phase error

ICP = 0 0.6

ICP = 1 1.2

10kΩ || 10pF load 0.5 1 V

When used as a passive input for an external reference
oscillator

When used as a passive input for an external reference
oscillator

Detector on 0.1 mA

Detector off 5 µA

= +25°C 2.7 5

A

< 1 20 ms

0 or
200

200 µs

12 kΩ

100 600 mV

Hz

dB

P-P

P-P

dB

mA

P-P

RMS

MAX2165

Single-Conversion DVB-H Tuner

_______________________________________________________________________________________ 5

AC ELECTRICAL CHARACTERISTICS (continued)

(MAX2165 EV kit, VCC= +2.75V to +3.3V, V

RF_AGC

= V

BB_AGC

= 2.3V (maximum gain), V

OUT

= 1V

P-P

, 75Ω system impedance, reg-

isters set according to the specified default register conditions, T

A

= -40°C to +85°C, unless otherwise noted. Typical values are at

V

CC

= +2.85V, TA= +25°C, unless otherwise noted.) (Note 1)

Note 1: Min and max limits are guaranteed by test at TA= +25°C and are guaranteed by design and characterization at TA=

-40°C and +85°C. The default register settings are not production tested. Load registers no sooner than 100µs after
power-up.

Note 2: Notch filter must be disabled by programming the TF_NTCH[3:0] bits to 1111 to enable operation up to 832MHz. Under

extreme conditions, the part can experience up to 3dB degradation in sensitivity and intermodulation distortion.

Note 3: Guaranteed by design and characterization over the specified operating conditions. Not production tested.
Note 4: UHF tones resulting in f

1

- f2beat frequency within the baseband output. Two tones at 350MHz and 1133MHz

with IM2 measured at 783MHz.

Note 5: Two tones converted to 5.25MHz and 10.75MHz, IM3 measured at 250kHz.
Note 6: A desired signal at P

DESIRED

= -78dBm is injected and downconverted to 3.75MHz. A blocker tone is injected at 10MHz

higher in frequency. Specified level is blocker power at which desired output signal compresses by 1dB. T

A

= +25°C.

Note 7: A single blocker at -7dBm with a bandwidth of less than 4MHz is injected at 880MHz with the receiver tuned to 783MHz

and set to maximum gain.

Note 8: VCO locked to within 100Hz of the Rx frequency. Wake-up initiated by toggling the SHDN pin from low to high and con-

necting the STBY pin to ground.

Note 9: Applies to continuous DC correction operation (DVB-T mode). In DVB-H mode, optional correction hold feature allows

quasi-DC-coupling.

Note 10: Depends on 7MHz/8MHz bandwidth mode.
Note 11: Equivalent to video carrier in upper adjacent channel. T

A

= +25°C.

Note 12: Equivalent to f

NYQUIST

- 3.8MHz for 18.3MHz sampling rate baseband DAC.

Note 13: Total frequency resolution is f

REF

/ 220, or approximately 20Hz with a 20MHz reference frequency.

Typical Operating Characteristics

(MAX2165 EV kit, VCC= +2.85V, default register settings, V

RF_AGC

= V

BB_AGC

= 2.3V, V

IOUT

= V

QOUT

= 500mV

P-P

, TA= +25°C,

unless otherwise noted.)

SUPPLY CURRENT vs. SUPPLY VOLTAGE

VCC (V)

I

CC

(mA)

MAX2165 toc01

2.6 2.8 3.0 3.2 3.4

100

105

110

115

120

TA = -40°C

TA = +85°C

TA = +25°C

VOLTAGE GAIN vs. FREQUENCY

FREQUENCY (MHz)

GAIN (dB)

MAX2165 toc02

470 535 600 665 730 795 860

65

70

75

80

85

90

95

100

TA = -40°C

TA = +85°C

TA = +25°C

VOLTAGE GAIN vs. RFAGC

MAX2165 toc03

2.01.51.00.5

40

50

60

70

80

90

30

0 2.5

TA = +85°C

TA = -40°C

TA = +25°C

BB_AGC = 2.3V

GAIN (dB)

RF_AGC CONTROL VOLTAGE (V)

PARAMETER CONDITIONS MIN TYP MAX UNITS

Detector Gain 150 V/V

Detector Response Time 5µs

2-WIRE SERIAL INTERFACE

Clock Rate I2C fast mode, slave category 400 kHz

MAX2165

Single-Conversion DVB-H Tuner

6 _______________________________________________________________________________________

PHASE

NOISE

(dB

/H

)

Typical Operating Characteristics (continued)

(MAX2165 EV kit, VCC= +2.85V, default register settings, V

RF_AGC

= V

BB_AGC

= 2.3V, V

IOUT

= V

QOUT

= 500mV

P-P

, TA= +25°C,

unless otherwise noted.)

VOLTAGE GAIN vs. BBAGC

90

RF_AGC = 2.3V

80

70

60

GAIN (dB)

50

40

30

0 0.5 1.0 1.5 2.0 2.5

BB_AGC CONTROL VOLTAGE (V)

TA = -40°C

MAX2165 toc04

TA = +25°C

TA = +85°C

NOISE FIGURE (dB)

NOISE FIGURE vs. FREQUENCY

12

9

TA = +85°C

6

3

0

470 535 600 665 730 795 860

TA = +25°C

TA = -40°C

FREQUENCY (MHz)

MAX2165 toc05

NOISE FIGURE vs. RF Tx INPUT POWER

20

BLOCKER AT 880MHz

15

10

NOISE FIGURE (dB)

5

0

-22.5-25.0 -20.0

-17.5

RF Tx INPUT POWER (dBm)

-12.5-15.0

-10.0

MAX2165 toc06

-7.5 -5.0

RF INPUT RETURN LOSS

vs. FREQUENCY

0

ZO = 75Ω

5

10

15

20

25

RETURN LOSS (dB)

30

35

TRACKING FILTER SETTING "7"

40

TRACKING FILTER SETTING "1"

TRACKING FILTER SETTING "15"

FREQUENCY (MHz)

PHASE NOISE vs. RF FREQUENCY

-60
10kHz OFFSET

-70

z
m

-80

-90

-100

-110
470 535 600 665 730 795 860

RF FREQUENCY (MHz)

NORMALIZED BASEBAND

FREQUENCY RESPONSE

5

MAX2165 toc07

860

795730665600535470

0

-5

-10

-15

GAIN (dB)

-20

-25

-30

3.0 3.5 4.0 4.5 5.0 5.5

A: +2 ADJUSTMENT FACTOR
B: +1 ADJUSTMENT FACTOR
C: 0 ADJUSTMENT FACTOR
D: -1 ADJUSTMENT FACTOR
E: -2 ADJUSTMENT FACTOR

MAX2165 toc10

F

G

H

I

E

FREQUENCY (MHz)

F: -3 ADJUSTMENT FACTOR
G: -4 ADJUSTMENT FACTOR
H: -5 ADJUSTMENT FACTOR
I: -6 ADJUSTMENT FACTOR

D

C

B

A

A

MAX2165 toc08

10.0
0

-10.0

-20.0

-30.0

-40.0

-50.0

GAIN (dB)

-60.0

-70.0

-80.0

-90.0

-100.0

-110.0

-50

-60

-70

NORMALIZED BASEBAND

FREQUENCY RESPONSE

+0 ADJUSTMENT FACTOR

+2 ADJUSTMENT FACTOR

-6 ADJUSTMENT FACTOR

02 4 20

86

1210

FREQUENCY (MHz)

1816

14

PHASE NOISE vs. OFFSET FREQUENCY

MAX2165 toc09

MAX2165 toc11

-80

-90

-100

-110

-120

-130

PHASE NOISE (dBm/Hz)

-140

-150

-160
1 10 100 1000 10,000

OFFSET FREQUENCY (kHz)

MAX2165

Single-Conversion DVB-H Tuner

_______________________________________________________________________________________ 7

Typical Operating Characteristics (continued)

(MAX2165 EV kit, VCC= +2.85V, default register settings, V

RF_AGC

= V

BB_AGC

= 2.3V, V

IOUT

= V

QOUT

= 500mV

P-P

, TA= +25°C,

unless otherwise noted.)

REFERENCE BUFFER OUTPUT SIGNAL

MAX2165 toc13

200mV/div

20ns/div

10kΩ || 10pF LOAD

Pin Description

POWER-DETECTOR OUTPUT VOLTAGE

4

3

2

1

POWER-DETECTOR OUTPUT VOLTAGE (V)

0

-70

vs. RF INPUT POWER

40kΩ PULLUP TO 2.85V

PD_TH[2:0] = 000

-60
RF INPUT POWER (dBm)

PD_TH[2:0] = 111

-50 -40

MAX2165 toc12

-30

PIN NAME FUNCTION

1 SDA Serial-Data Input/Output. Requires a pullup resistor to VCC.

2 SCL Serial-Clock Input. Requires a pullup resistor to VCC.

3 N.C. No Connection. Connect this pin to ground.

4 RFIN RF Input. Internally matched to 75Ω. Requires a DC-blocking capacitor.

5 ADDR Address-Select Input. Selects the I2C slave address. See Table 20.

6 VCC_RF

RF Power-Supply Input. Connect to a low-noise, power-supply voltage. Bypass to the PCB ground
plane with a 2200pF and 100nF capacitor placed as close as possible to the pin.

7 LEXT External Inductor Connection. Connect to V

8 RF_AGC

9 SHDN

10 STBY

11 OVLD_DET

12 VCC_BB

RF Gain-Control Voltage Input. Accepts voltages from 0.4V to 2.3V with 2.3V providing maximum RF
gain. This pin can also be controlled by the OVLD_DET output. See the Typical Application Circuit.

Shutdown Input. Drive this pin low to disable all internal circuits and to put the device into low-power
shutdown mode. Drive this pin high for normal operation.

Standby Input. Controls the power-up sequence of the chip. See the Power-Up Sequence section for
more information on this pin’s operation.

Overload-Detection Output. This output provides an error signal between the internal power-detector
output voltage and an internal programmable reference voltage. This output can be connected to the
RF_AGC input to implement a closed RF automatic gain-control loop.

Baseband Power-Supply Input. Connect to a low-noise power-supply voltage. Bypass to the PCB
ground plane with a 1000pF and 100nF capacitor placed as close as possible to the pin.

13 BBQ- Inverting Quadrature Baseband Output

with a 39nH inductor.

CC

MAX2165

Detailed Description

Register Descriptions

The MAX2165 includes 15 programmable registers and
three read-only registers. See Table 1 for register con­figurations. The register configuration of Table 1 shows
each bit name and the bit usage information for all reg­isters. U labeled under each bit name indicates that the
bit value is user defined to meet specific application

requirements. A 0 or 1 indicates that the bit must be set
to the defined 0 or 1 value for proper operation.
Operation is not tested or guaranteed if these bits are
programmed to other values and is only for
factory/bench evaluation. In typical application, always
program to the operation defined state.

See Tables 2–19 for detailed descriptions of each reg­ister. All registers must be written 100µs after power-up
and no earlier than 100µs after power-up.

Single-Conversion DVB-H Tuner

8 _______________________________________________________________________________________

Pin Description (continued)

PIN NAME FUNCTION

14 BBQ+ Noninverting Quadrature Baseband Output

15 BBI- Inverting In-Phase Baseband Output

16 BBI+ Noninverting In-Phase Baseband Output

17 BB_AGC

18 VCC_VCO

19 VTUNE VCO Tuning Voltage Input. Connect to the PLL loop filter output.

20 GND_TUNE VCO Tuning Voltage Ground. Connect to the PCB ground plane.

21 LDO

22 CP Charge-Pump Output. Connect to the PLL loop filter input.

23 VCC_SYN

24 MUX

Baseband Gain-Control Voltage Input. Accepts voltages from 0.4V to 2.3V with 2.3V providing the
maximum baseband gain.

VCO Power-Supply Input. Connect to a low-noise power-supply voltage. Bypass to the PCB ground
plane with a 1000pF and 100nF capacitor placed as close as possible to the pin.

VCO Linear-Regulator Noise Bypass. Bypass to the PCB ground plane with a 470nF capacitor placed
as close as possible to the pin.

Synthesizer Power-Supply Input. Connect to a low-noise power-supply voltage. Bypass to the PCB
ground plane with a 1000pF and 100nF capacitor placed as close as possible to the pin.

Multiplexed Output Line. Output for various test functions, can also be used as a PLL lock-detect
indicator. See Table 9 for more information. When used as a PLL lock detector, logic-high indicates
PLL is not locked and logic-low indicates PLL is locked.

25 REFOUT

26 VCC_XTAL

27 XB

28 XE

EP EP Exposed Paddle. Solder evenly to the board’s ground plane to achieve the lowest impedance path.

Reference Buffer Output. Provides a buffered crystal-oscillator signal that can be used as a clock
reference for the demodulator. Requires a DC-blocking capacitor.

Crystal-Oscillator Power-Supply Input. Connect to a low-noise power-supply voltage. Bypass to the
PCB ground plane with a 1000pF and 100nF capacitor placed as close as possible to the pin.

Reference Input. Connect to a parallel resonant mode crystal through a load-matching capacitor or to
a reference oscillator.

Reference-Oscillator Feedback Input. Connect to a capacitive feedback network when the on-chip
reference oscillator is used. Leave unconnected when an external reference is used.