The LMX2571-EP device is a low-power, high-performance, wideband PLLatinum™ RF synthesizer that integrates a delta-sigma fractional N PLL, multiple core voltage-controlled oscillator (VCO), programmable output dividers and two output buffers. The VCO cores work up to 5.376 GHz resulting in continuous output frequency range of 10 MHz to 1344 MHz.
This synthesizer can also be used with an external VCO. To that end, a dedicated 5-V charge pump and an output divider are available for this configuration.
A unique programmable multiplier is also incorporated to help improve spurs, allowing the system to use every channel even if it falls on an integer boundary.
The output has an integrated SPDT switch that can be used as a transmit and receive switch in FDD radio application. Both outputs can also be turned on to provide 2 outputs at the same time.
The LMX2571-EP supports direct digital FSK modulation through programming or pins. Discrete level FSK, pulse shaping FSK, and analog FM modulation are supported.
A new FastLock technique can be used allowing the user to step from one frequency to the next in less than 1.5 ms even when an external VCO is used with a narrow band loop filter.
PART NUMBER | PACKAGE | BODY SIZE (NOM) |
---|---|---|
LMX2571-EPV62/21613-01XE | VQFN (36) | 6.00 mm × 6.00 mm |
Changes from Revision A (December 2021) to Revision B (June 2022)
Changes from Revision * (October 2021) to Revision A (December 2021)
PIN | TYPE | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
Bypass1 | 2 | Bypass | Place a 100-nF capacitor to GND. |
Bypass2 | 3 | Bypass | Place a 100-nF capacitor to GND. |
CE | 19 | Input | Chip Enable input. Active HIGH powers on the device. |
CLK | 11 | Input | MICROWIRE clock input. |
CPout | 25 | Output | Internal VCO charge pump access point to connect to a 2nd order loop filter. |
CPoutExt | 30 | Output | 5-V charge pump output used in PLL mode (external VCO). |
DAP | GND | GND | The DAP should be grounded. |
DATA | 12 | Input | MICROWIRE serial data input. |
Fin | 24 | Input | High-frequency, AC-coupled input pin for an external VCO. Leave it open or AC-coupled to GND if not being used. |
FSK_D0 | 7 | Input | FSK data bit 0 (FSK PIN mode) / I2S FS input (FSK I2S mode). |
FSK_D1 | 6 | Input | FSK data bit 1 (FSK PIN mode) / I2S DATA input (FSK I2S mode). |
FSK_D2 | 5 | Input | FSK data bit 2 (FSK PIN mode). |
FSK_DV | 4 | Input | FSK data valid input (FSK PIN mode) / I2S CLK input (FSK I2S mode). |
FLout1 | 29 | Output | FastLock output control 1 for external switch. Output is HIGH when F1 is selected. |
FLout2 | 28 | Output | FastLock output control 2 for external switch. Output is HIGH when F2 is selected. |
GND | 23 | GND | VCO ground. |
GND | 31 | GND | Charge pump ground. |
GND | 35 | GND | OSCin ground. |
LE | 13 | Input | MICROWIRE latch enable input. |
MUXout | 10 | Output | Multiplexed output that can be assigned to lock detect or readback serial data output. |
NC | 14, 26 | NC | Leave floating, do not connect to GND or power supply. |
OSCin | 34 | Input | Reference clock input. |
NC | 8,18, 36 | NC | These pins may be left floating or connected to GND. |
RFoutRx | 16 | Output | RF output used to drive receive mixer. Selectable open-drain or push-pull output. |
RFoutTx | 17 | Output | RF output used to drive transmit signal. Selectable open-drain or push-pull output. |
Vcc3p3 | 1, 9, 20, 27 | Supply | Connect to 3.3-V supply. |
VccIO | 15, 33 | Supply | Supply for digital logic interface. Connect to 3.3-V supply. |
VcpExt | 32 | Supply | Supply for 5-V charge pump. Connect to 5-V supply in PLL mode. Connect to either 3.3-V or 5-V supply in synthesizer mode. |
VrefVCO | 22 | Bypass | LDO output. Place a 100-nF capacitor to GND. |
VregVCO | 21 | Bypass | Bias circuitry for the VCO. Place a 2.2-µF capacitor to GND. |
MIN | MAX | UNIT | ||
---|---|---|---|---|
VCC | Power supply voltage | –0.3 | 3.6 | V |
VIO | IO supply voltage | –0.3 | 3.6 | V |
VCP | Charge pump supply voltage | 5.25 | V | |
VIN | IO input voltage | VCC + 0.3 | V | |
TJ | Junction temperature | –55 | 150 | °C |
Tstg | Storage temperature | –65 | 150 | °C |
VALUE | UNIT | |||
---|---|---|---|---|
V(ESD) | Electrostatic discharge | Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins(1) | ±1500 | V |
Charged device model (CDM), per ANSI/ESDA/JEDEC JS-002, all pins(2) | ±500 |