SNAS665 May 2015 LMX2581E
PRODUCTION DATA.
PIN | TYPE | DESCRIPTION | |
---|---|---|---|
NUMBER | NAME | ||
0 | DAP | GND | The DAP should be grounded. |
1 | CLK | Input | MICROWIRE Clock Input. High Impedance CMOS input. |
2 | DATA | Input | MICROWIRE Data. High Impedance CMOS input. |
3 | LE | Input | MICROWIRE Latch Enable. High Impedance CMOS input. |
4 | CE | Input | Chip Enable Pin. |
5 | FLout | Output | Fastlock Output. This can switch in an external resistor to the loop filter during locking to improve lock time. |
6 | VccCP | Supply | Charge Pump Supply. |
7 | CPout | Output | Charge Pump Output. |
8 | GND | GND | Ground for the Charge Pump. |
9 | GND | GND | Ground for the N and R divider. |
10 | VccPLL | Supply | Supply for the PLL. |
11 | Fin | Input | High frequency input pin for an external VCO. Leave Open or Ground if not used. |
12 | RFoutA+ | Output | Differential divided output. For single-ended operation, terminate the complimentary side with a load equivalent to the load at this Pin. |
13 | RFoutA- | Output | Differential divided output. For single-ended operation, terminate the complimentary side with a load equivalent to the load at this pin. |
14 | RFoutB+ | Output | Differential divided output. For single-ended operation, terminate the complimentary side with a load equivalent to the load at this pin. |
15 | RFoutB- | Output | Differential divided output. For single-ended operation, terminate the complimentary side with a load equivalent to the load at this pin. |
16 | VccBUF | Supply | Supply for the Output Buffer. |
17 | VccVCO | Supply | Supply for the VCO. |
18 | GND | GND | Ground Pin for the VCO. This can be attached to the regular ground. Ensure a solid trace connects this pin to the bypass capacitors on pins 19, 23, and 24. |
19 | VbiasVCO | Output | Bias circuitry for the VCO. Place a 2.2 µF capacitor to GND (Preferably close to Pin 18). |
20 | Vtune | Input | VCO tuning voltage input. See the functional description regarding the minimum capacitance to put at this pin. |
21 | GND | GND | VCO ground. |
22 | VrefVCO | Output | VCO capacitance. Place a capacitor to GND (Preferably close to Pin 18). This value should be between 5% and 10% of the capacitance at pin 24. Recommended value is 1 µF. |
23 | VbiasCOMP | Output | VCO bias voltage temperature compensation circuit. Place a minimum 10 µF capacitor to GND (Preferably close to Pin 18). If it is possible, use more capacitance to slightly improve VCO phase noise. |
24 | VregVCO | Output | VCO regulator output. Place a minimum 10 µF capacitor to GND (Preferably close to Pin 18). If it is possible, use more capacitance to slightly improve VCO phase noise. |
25 | LD | Output | Multiplexed output that can perform lock detect, PLL N and R counter outputs, Readback, and other diagnostic functions. |
26 | BUFEN | Input | Enable pin for the RF output buffer. If not used, this can be overwritten in software. |
27 | GND | GND | Digital Ground. |
28 | VccDIG | Supply | Digital Supply. |
29 | OSCin | Input | Reference input clock. |
30 | MUXout | Output | Multiplexed output that can perform lock detect, PLL N and R counter outputs, Readback, and other diagnostic functions.. |
31 | GND | GND | Ground for the fractional circuitry. |
32 | VccFRAC | Supply | Supply for the fractional circuitry. |