Background

Power management and conversion IC’s are found in all end-user systems for industrial, automotive, computing and consumer electronics markets. For many applications (voltage regulators, battery power management, DC/DC converters) the different vendors heavily compete on cost and improved convenience for system makers. They need low cost production to beat the competition. Since the on-chip digital logic circuit is typically limited, IC makers use mature technology nodes (1um to 0.18um) to cut costs. Most applications require specialized analog circuitry. For some applications High Voltage compatibility is ensured through the inclusion of specialized HV devices (DENMOS, graded drain junction MOS).

ESD complexity

While public ESD solutions for mature technologies can cover many interface types, the custom analog circuitry in the power management IC’s require optimized solutions. For end-user convenience, the IC’s need to include all kinds of protection (e.g. over voltage, temperature shut-down, …). Certainly the High Voltage interfaces feature sensitive transistors and add parasitic elements to be taken into account.
In many cases, the IC’s require higher than standard ESD specifications.

Experience from Sarnoff

Sarnoff has developed ESD solutions for a number of power management IC’s such as motor driver applications, Class D amplifiers, voltage detector IC’s, voltage regulators, battery chargers...

• 1.2um BCD 60V
• 0.7um HV CMOS 100V
• 0.7um HV CMOS 50V
• 0.6um BiCD Bipolar, CMOS, DMOS 40V
• 0.5um BiCMOS 22V

Applications available on the market including TakeCharge ESD solutions:

Application	CMOS node
Battery management IC’s	0.6um – 0.5um
LDO	0.5um
DC-DC converters	0.6um
Voltage detectors	0.6um

   
Example:

• Mobile phone battery management IC: Li-ion
• 0.6um CMOS, Analog circuit
• 8kV IEC achieved

Key technical benefits for working with Sarnoff

IC designers have worked with Sarnoff to reduce the die cost by drastically shrinking the IO area.
Sarnoff has focused on different items:

• Area efficient solutions: win business, volume and margins
• Scalable ESD performance: reach any ESD requirement
• Low leakage and Latch-up immune
• Over voltage and under voltage tolerant options available
• Complete solution package and technology understanding to allow protection of complete custom analog circuitry.
• No need for process changes for ESD solutions

Customer testimonials

• Ryo Ogura, the ESD project leader and Managing Director of NJR
  • “Smaller ICs can help LCD display manufacturers meet the cost pressures they face, and also offer an opportunity to develop even more compact designs. Our engineers achieved this breakthrough IC design for our customers just 8 months after we implemented the new technology, with no redesigns required.”
  • New Japan Radio announced that its engineering team has achieved a reduction of 33% in driver size and a drastic decrease in overall device size for LCD driver ICs. The company used a customized version of the TakeCharge® design technology.   [read more]
• Fumihisa Nakamura, Category Director, Display Driver and PDP, System LSI Division of Matsushita Semiconductor Company
  • “TakeCharge technology can reduce the capacitance of the input and output (I/O) pins of HV-CMOS IC’s. Therefore, its application can reduce the power required to drive the data bus”

Relevant conference and journal publications

Sarnoff engineers frequently publish technical peer-reviewed papers about the TakeCharge ESD solutions. A selection of these publications regarding high-speed interfaces is provided below

• ESD protection solutions for high voltage technologies – Microelectronics Reliability (2005)
• High Holding Current SCRs (HHI-SCR) for ESD Protection and Latch-up Immune IC Operation – EOS/ESD symposium (2002)