LMX2694-EP 器件是一款集成电压控制振荡器 (VCO) 和稳压器的高性能宽带锁相环 (PLL),在无倍频器的情况,可输出 39.3MHz 至 15.1GHz 范围内的任意频率,从而无需使用 ½ 谐波滤波器。此器件上的 VCO 涵盖了整个倍频区间,因而频率覆盖度可完全低至 39.3MHz。该高性能 PLL 具有 -236dBc/Hz 的品质因数和高相位检测器频率,可实现非常低的带内噪声和集成抖动。
LMX2694-EP 允许设计人员同步多个器件实例的输出。这意味着我们可从任意应用情形下的器件中获得确定性相位,包括采用分数引擎或启用输出分频器的情形。该器件还让设计人员可以生成或重复 SYSREF(符合 JESD204B 标准),以便将该器件用作高速数据转换器的低噪声时钟源。
器件型号 | 封装 | 封装尺寸(标称值) |
---|---|---|
LMX2694-EP | VQFN (48) | 7.00mm × 7.00mm |
Changes from Revision C (October 2021) to Revision D (March 2022)
Changes from Revision B (May 2020) to Revision C (October 2021)
Changes from Revision A (December 2019) to Revision B (May 2020)
Changes from Revision * (November 2019) to Revision A (December 2019)
PIN | I/O | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
BIASVARAC | 41 | BP | VCO varactor bias. Connect a 10-µF decoupling capacitor to ground. |
BIASVCO | 3 | BP | VCO bias. Connect a 10-µF decoupling capacitor to ground. Place close to pin. |
BIASVCO2 | 34 | BP | VCO bias. Connect a 1-µF decoupling capacitor to ground. Place close to pin. |
CE | 1 | I | Chip Enable. High impedance CMOS input. 1.8-V to 3.3-V logic. Active HIGH powers on the device. |
CPOUT | 14 | O | Charge pump output. Recommend connecting C1 of loop filter close to this pin. |
CS# | 28 | I | SPI latch. High impedance CMOS input. 1.8-V to 3.3-V logic. |
GND | 2, 4, 32, 40, 42, 47 | G | VCO ground. |
GND | 6, 16, 48 | G | Digital ground. |
GND | 15 | G | Charge pump ground. |
GND | 27, 29 | G | Buffer ground. |
MUXOUT | 23 | O | Multiplexed output. Can output: lock detect, SPI readback and diagnostics. |
NC | 11, 12, 20, 30, 31, 37, 38, 39 | NC | Pins may be grounded or left unconnected. |
OSCIN_N | 9 | I | Reference input clock (–). High impedance self-biasing pin. Requires AC-coupling capacitor. (0.1 µF recommended) |
OSCIN_P | 8 | I | Reference input clock (+). High impedance self-biasing pin. Requires AC-coupling capacitor. (0.1 µF recommended) |
REFVCO | 44 | BP | VCO supply reference. Connect a 10-µF decoupling capacitor to ground. |
REFVCO2 | 36 | BP | VCO supply reference. Connect a 10-µF decoupling capacitor to ground. |
REGIN | 10 | BP | Input reference path regulator decoupling. Connect a 1-µF decoupling capacitor to ground. Place close to pin. |
REGVCO | 46 | BP | VCO regulator node. Connect a 1-µF decoupling capacitor to ground. |
RFOUTA_N | 25 | O | Differential output A (–). Requires connecting 50-Ω resistor pullup to VCC as close as possible to pin. |
RFOUTA_P | 26 | O | Differential output A (+). Requires connecting 50-Ω resistor pullup to VCC as close as possible to pin. |
RFOUTB_N | 21 | O | Differential output B (–). Requires connecting 50-Ω resistor pullup to VCC as close as possible to pin. |
RFOUTB_P | 22 | O | Differential output B (+). Requires connecting 50-Ω resistor pullup to VCC as close as possible to pin. |
SCK | 18 | I | SPI clock. High impedance CMOS input. 1.8-V to 3.3-V logic. |
SDI | 19 | I | SPI data. High impedance CMOS input. 1.8-V to 3.3-V logic. |
SYNC | 5 | I | Phase synchronization input. Has programmable threshold. Connect to ground if not being used. |
SYSREFREQ | 35 | I | SYSREF request input for JESD204B support. Connect to ground if not being used. |
VCCBUF | 24 | P | Output buffer supply. Connect to 3.3-V and a 0.1-µF decoupling capacitor to ground. |
VCCCP | 13 | P | Charge pump supply. Connect to 3.3-V and a 0.1-µF decoupling capacitor to ground. |
VCCDIG | 7 | P | Digital supply. Connect to 3.3-V and a 0.1-µF decoupling capacitor to ground. |
VCCMASH | 17 | P | Digital supply. Connect to 3.3-V and a 1-µF decoupling capacitor to ground. |
VCCVCO | 45 | P | VCO supply. Connect to 3.3-V and a 1-µF decoupling capacitor to ground. |
VCCVCO2 | 33 | P | VCO supply. Connect to 3.3-V and a 1-µF decoupling capacitor to ground. |
VTUNE | 43 | I | VCO tuning voltage input. Connect a 1.5-nF or more capacitor to VCO ground. See Section 8.1.6 for details. |
Thermal pad | — | — | Connect the GND pin to the exposed thermal pad for correct operation. Connect the thermal pad to any internal PCB ground plane using multiple vias for good thermal performance. |
MIN | MAX | UNIT | ||
---|---|---|---|---|
VCC | Power supply voltage | –0.3 | 3.6 | 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(1) | ±1000 | V |
Charged device model (CDM), per JEDEC specification JESD22-C101, all pins(2) | ±1000 |
MIN | NOM | MAX | UNIT | ||
---|---|---|---|---|---|
TC | Case temperature | –55 | 125 | °C | |
VCC | Supply input voltage | 3.2 | 3.3 | 3.45 | V |
THERMAL METRIC(1) | LMX2694-EP | UNIT | |
---|---|---|---|
RTC (VQFN) | |||
48 PINS | |||
RθJA | Junction-to-ambient thermal resistance | 22.4 | °C/W |
RθJC(top) | Junction-to-case (top) thermal resistance | 10.0 | °C/W |
RθJB | Junction-to-board thermal resistance | 6.1 | °C/W |
ΨJT | Junction-to-top characterization parameter | 0.1 | °C/W |
ΨJB | Junction-to-board characterization parameter | 6.0 | °C/W |
RθJC(bot) | Junction-to-case (bottom) thermal resistance | 0.7 | °C/W |