Overview
The LMK5B12204RGZR, produced by Texas Instruments, is a high-performance network synchronizer clock device designed to meet the stringent timing requirements of communications infrastructure and industrial applications. This device offers ultra-low jitter, advanced clock monitoring, and superior hitless switching performance. It integrates a digital phase-locked loop (DPLL) and two analog phase-locked loops (APLLs) to provide industry-leading jitter performance and flexible clock generation capabilities. The LMK5B12204 utilizes Texas Instruments' proprietary Bulk Acoustic Wave (BAW) VCO technology to generate output clocks with exceptionally low jitter, independent of the jitter and frequency of the input references.
Key Specifications
| Parameter | Min | |||
|---|---|---|---|---|
| VDD (Core Supply Voltage) | -0.3 | 3.6 | V | |
| VDDO (Output Supply Voltage) | -0.3 | 3.6 | V | |
| TJ (Junction Temperature) | 150 | °C | ||
| Tstg (Storage Temperature Range) | -65 | 150 | °C | |
| IDD_DIG (Core Current Consumption, VDD_DIG) | 21 | mA | ||
| IDD_PLL1 (Core Current Consumption, VDD_PLL1) | 110 | mA | ||
| fIN (Input Frequency Range, Differential Input) | 5 | 800 | MHz | |
| fVCO1 (VCO1 Frequency Range) | 2499.750 | 2500 | 2500.250 | MHz |
| fVCO2 (VCO2 Frequency Range) | 5500 | 6250 | MHz | |
| Output Jitter (APLL1 at 312.5 MHz) | 50 | fs RMS | ||
| Output Jitter (APLL2 at 155.52 MHz) | 125 | fs RMS |
Key Features
- One Digital Phase-Locked Loop (DPLL) with hitless switching (±50-ps phase transient), programmable loop bandwidth, and fastlock capability.
- Two Analog Phase-Locked Loops (APLLs) with industry-leading jitter performance: 50-fs RMS jitter at 312.5 MHz (APLL1) and 125-fs RMS jitter at 155.52 MHz (APLL2).
- Two reference clock inputs with priority-based input selection and digital holdover on loss of reference.
- Four clock outputs with programmable drivers supporting various output formats: AC-LVDS, AC-CML, AC-LVPECL, HCSL, and 1.8-V LVCMOS.
- EEPROM/ROM for custom clock configurations on power-up.
- Flexible configuration options: input frequencies from 1 Hz to 800 MHz, and XO/TCXO/OCXO input range of 10 to 100 MHz.
- Full programmability through I2C or SPI interface.
- Advanced reference input monitoring and robust clock fault detection.
- Support for IEEE 1588 PTP slave mode with less than 0.001-ppb frequency step size.
Applications
The LMK5B12204 is designed for use in various high-performance applications, including:
- Communications infrastructure: wireless base stations, Ethernet switches, and optical transport networks.
- Industrial applications: industrial automation, medical devices, and high-speed data acquisition systems.
- Networking equipment: routers, switches, and network interface cards.
- Test and measurement equipment: requiring precise clock generation and low jitter.
Q & A
- What is the primary function of the LMK5B12204?
The LMK5B12204 is a high-performance network synchronizer clock device that provides jitter cleaning, clock generation, advanced clock monitoring, and superior hitless switching performance.
- What types of phase-locked loops are integrated into the LMK5B12204?
The device includes one digital phase-locked loop (DPLL) and two analog phase-locked loops (APLLs).
- What is the jitter performance of the APLLs in the LMK5B12204?
The APLLs offer industry-leading jitter performance: 50-fs RMS jitter at 312.5 MHz (APLL1) and 125-fs RMS jitter at 155.52 MHz (APLL2).
- How many clock outputs does the LMK5B12204 support?
The device supports four clock outputs with programmable drivers.
- What output formats are supported by the LMK5B12204?
The device supports AC-LVDS, AC-CML, AC-LVPECL, HCSL, and 1.8-V LVCMOS output formats.
- How is the LMK5B12204 programmed?
The device is fully programmable through I2C or SPI interface and supports custom frequency configuration on power-up using internal EEPROM or ROM.
- What is the operating temperature range of the LMK5B12204?
The operating temperature range is -40°C to 85°C.
- What is the package type and pin count of the LMK5B12204?
The device is available in a VQFN (48) package.
- Does the LMK5B12204 support IEEE 1588 PTP slave mode?
Yes, the device supports IEEE 1588 PTP slave mode with less than 0.001-ppb frequency step size.
- What is the purpose of the hitless switching feature in the LMK5B12204?
The hitless switching feature ensures seamless transition between reference clocks with minimal phase transient (±50 ps).
