LDO regulator is first for satellite power, claims Renesas Electronics
Believed to be the industry’s first radiation-hardened (rad-hard) single-chip synchronous buck and low dropout (LDO) regulator for satellite power applications, the ISL70005SEH has been released by Renesas Electronics.
It reduces bill of materials (BoM), size, weight and power (SWaP) for FPGAs and DDR memories and other digital loads for spaceflight payload applications, says Renesas.
The ISL70005SEH is believed to be the only point-of-load (POL) power device to integrate a synchronous buck and LDO in one monolithic IC. The regulator enables satellite manufacturers to reduce BoM and power supply footprint for medium Earth orbit (MEO) and geosynchronous Earth orbit (GEO) long duration mission profiles.
The ISL70005SEH rad-hard dual output PoL regulator combines 95 per cent high efficiency with the synchronous buck regulator and a low 75mV dropout on the LDO regulator. It enables easier thermal management for systems with 3.3 or 5V power buses and can support 3A continuous output load current for the buck regulator and ±1A for the LDO. The buck regulator uses a voltage mode control architecture and switches at a resistor adjustable frequency of 100kHz to 1MHz, enabling a smaller filter size.
In addition to the advantages of superior radiation performance and SWaP and BoM savings, Philip Chesley, VP, Industrial and Communications business division at Renesas points out: “Our dual output PoL regulator also provides the configurability to address multiple applications in commercial telecommunication satellites, military satcom satellites, and science and exploration missions.”
The space-grade ISL70005SEH can be used as a dual output regulator, DDR memory power solution or high efficiency low noise regulator for RF applications. The LDO can source and sink current and accept input voltages as low as 775mV to reduce unnecessary power dissipation. The externally adjustable loop compensation on the buck allows users to achieve an optimal balance of stability and output dynamic performance. The device is wafer acceptance tested to 100krad(Si) over high dose rate (HDR) and tested for ELDRS up to 75krad(Si) over low dose rate (LDR). Single event effects (SEE) testing shows no single event latch-up (SEL) and single event burnout (SEB) at a linear energy transfer (LET) up to 86MeV cm2/mg. Single event transients (SETs) have been characterised at a LET range of 8.5 to 86MeV cm2/mg.
The ISL70005SEH is suitable for both FPGA core and I/O rails and can be combined with Renesas analogue signal chain ICs to create a satellite telemetry solution, using an ISL70444SEH 40V quad operational amplifier, an ISL71840SEH 30V 16-channel multiplexer, an ISL70591SEH 100µA precision current source and ISL71090SEH12 1.25V precision voltage reference.
The ISL70005SEH radiation-hardened dual output POL regulator is available now in a 28-lead ceramic dual flatpack package or in die form. An evaluation board is also available.