XH311HG-IV07E SEIKO EDLC Supercapacitor: Applications, Selection Guide, Alternatives and Buying Notes

XH311HG-IV07E SEIKO EDLC supercapacitor is a Seiko Instruments XH-HG series coin-type Electric Double Layer Capacitor for compact 3.3V backup rails. It is used where an RTC, memory domain or small retention circuit needs short-duration energy after the main supply is removed. Key verified points include 20 mF / 0.02 F capacitance, 3.3V maximum charging, 3.8 mm diameter and SMD tabs, coin package with wide and corner terminals. View the XH311HG-IV07E product detail page or contact In-Fortune for sourcing support.

What is XH311HG-IV07E?

XH311HG-IV07E is not a primary coin battery and should not be described as a replaceable battery cell. It is an EDLC backup component: a very small capacitor optimized for board-mounted retention energy. In practical design terms, it sits on a backup node that only powers the circuitry that must remain alive during a short power interruption. That node may include a real-time clock, a few registers, SRAM retention, a counter, a sensor state register or a microcontroller backup domain.

The SEIKO XH-HG family is useful where board area and height are tight but the required backup current is very low. The electrical values tell whether the hold-up calculation works; the suffix tells whether the mechanical land pattern works.

How XH311HG-IV07E is used

Typical backup circuit role

In a typical circuit, XH311HG-IV07E is connected to a stable 3.3V backup rail through a controlled charge path. The main supply charges the EDLC while the equipment is operating. When the main rail falls, a diode, load switch or power-management circuit isolates the rest of the board so only the backup domain is powered. The retained load should be measured in microamps; radios, relays, displays and motors are outside the normal RTC and memory-retention use case.

The charge rail deserves careful review. Seiko data for these XH-HG parts uses a 3.3V maximum charge condition and CC/CV charging with a 500 uA maximum current in the test condition. The datasheet notes also warn against ripple charging and point out that higher charge voltage, temperature and humidity accelerate aging. Use a clean charge source, current limiting and a leakage calculation that includes the EDLC, protection path and backup IC pins.

Pinout and PCB footprint considerations

The XH311HG-IV07E pinout is mostly a terminal and polarity question. Unlike an IC, there is no logic pin map; the critical information is which tab is positive, which pad is negative, where the coin body sits and how the SMD terminal lands survive reflow and mechanical stress. The IV07E suffix identifies the compact terminal layout used by the XH311HG family; the exact land pattern must be checked from the terminal drawing.

This matters in purchasing as much as it matters in CAD. A request that says only XH414HG or XH311HG can lead to a part with the right voltage and capacitance but the wrong solder footprint. Freeze the full model number, including IV07E, when the layout is approved.

Key specifications for XH311HG-IV07E

XH311HG-IV07E selection guide

Select XH311HG-IV07E when the design needs space-constrained RTC or memory-retention rails where the load is very low and the 20 mF class gives enough hold-up margin. The choice is not only about capacitance; it is the combination of EDLC behavior, 3.3V charging, SMD assembly and the specific terminal geometry. the smallest board area among these three models, with less reserve energy than the XH414HG versions can be the deciding point in small meters, portable instruments, wireless modules and compact industrial controllers.

Before selecting the part, calculate retention time from measured load current. Start with the minimum operating voltage of the backup IC, charged EDLC voltage, leakage across the protection path and capacitance derating assumptions. If the hold-up time has no margin, move to a larger capacitance class or another energy-storage approach before PCB release.

Do not select XH311HG-IV07E for systems that need long backup duration, high pulse current, user replacement, or a board already released around the larger 4.8 mm XH414HG footprint. It is also a poor match for long calendar backup, high current pulses or a charging source that cannot be limited to the EDLC rating. For regulated equipment, review lifecycle and compliance documentation before design-in.

Alternatives and cross references for XH311HG-IV07E

XH311HG-IV07E alternatives should be treated as engineering candidates, not automatic replacements. Before approving a replacement, compare the datasheet, terminal polarity, package outline, PCB footprint, rated voltage, capacitance, internal impedance or ESR behavior, leakage, charge profile, reflow limits, temperature range, lifecycle status and compliance records.

Useful comparison targets include XH414HG-II06E, XH414HG-IV01E and other low-profile backup components, but the replacement decision must be based on the released schematic, land pattern and application risk. Do not substitute a different chemistry or suffix without engineering approval.

Buying notes and sourcing checks

Before sending an RFQ for XH311HG-IV07E, confirm the complete manufacturer part number, SEIKO / Seiko Instruments brand wording, XH-HG series, terminal suffix, packaging method, date code expectation, batch consistency, original factory condition, compliance document needs, lead time and approved substitute range. Ask the supplier whether lifecycle information or PCN history affects the purchase decision.

For manufacturing, confirm reflow profile, maximum reflow passes, polarity marking, tape orientation and inspection criteria. For engineering, confirm the 3.3V charge limit, maximum charge current, backup-load current, reverse current path and minimum voltage needed by the retained domain. Review the In-Fortune XH311HG-IV07E product detail page. Request sourcing support for XH311HG-IV07E. Contact In-Fortune to confirm XH311HG-IV07E specifications. Send an RFQ with your required quantity and delivery schedule.

XH311HG-IV07E SEIKO FAQ

Where can I find the XH311HG-IV07E datasheet?

Use the XH-HG or base-family Seiko Instruments datasheet as the first electrical reference, then confirm the exact suffix drawing with the supplier. The suffix is important because terminal geometry affects the PCB footprint.

What is the XH311HG-IV07E pinout?

For this EDLC, pinout mainly means polarity, SMD tab position and the recommended land pattern. The IV07E suffix identifies the compact terminal layout used by the XH311HG family; the exact land pattern must be checked from the terminal drawing. Always check the terminal drawing before releasing the PCB.

What applications fit XH311HG-IV07E?

XH311HG-IV07E fits low-current backup domains such as RTC, small memory retention, counters, configuration registers and compact portable or industrial electronics that can charge from a stable 3.3V rail.

Can XH311HG-IV07E replace a rechargeable lithium battery?

Not without review. An EDLC and a rechargeable lithium backup cell use different energy storage behavior, leakage profile, charge requirements, discharge curve and safety documentation.

Can another XH-HG terminal suffix replace XH311HG-IV07E?

Only after the PCB footprint, enclosure keep-out, soldering process and polarity are checked. A suffix change can be mechanically incompatible even when capacitance and voltage look similar.

What should procurement confirm before sourcing XH311HG-IV07E?

Confirm the full part number, SEIKO / Seiko Instruments brand, terminal suffix, packaging method, date code expectation, batch consistency, original condition, compliance documents, lead time and approved substitute range.

Suggested internal links for XH311HG-IV07E

• View the XH311HG-IV07E product detail page
• In-Fortune exact model search for XH311HG-IV07E
• SEIKO / Seiko Instruments manufacturer page on In-Fortune
• In-Fortune electronic component product catalogue
• XH414HG-II06E SEIKO EDLC article
• XH414HG-IV01E SEIKO EDLC article

Missing or uncertain data for XH311HG-IV07E

• Exact suffix terminal drawing, solder-land geometry and tape orientation: to be confirmed with supplier before PCB release.
• Current SEIKO / Seiko Instruments lifecycle, PCN history and approved last-buy or replacement path: to be confirmed with supplier.
• RoHS, REACH, customer-specific compliance packet and transport documentation requirements: to be confirmed with supplier.
• Packaging method, date-code range, batch consistency and acceptable substitute list for the purchase order: to be confirmed with supplier.