1-Cell protection IC for Li-Ion / Li-Polymer batteries with reset and forced standby function

Campbell, CA, June 8, 2021 - Ricoh Electronic Devices Co., Ltd. in Japan has launched the R5613, a primary battery protection IC for rechargeable 1-cell Lithium-Ion and Lithium Polymer batteries. It is designed to enforce strict usage limits keeping the battery cell in optimal condition and preventing critical overload conditions. Target applications are Li-Ion batteries or battery packs for portable devices such as smartphones, smartwatches, fitness trackers or other electronic gadgets.

Ricoh is a pioneer and has over 20 years of experience in developing battery protection ICs, the new R5613 features standard functions like over-charge and over-discharge voltage, excess load and excess charge current and a short circuit protection. Several advanced functions were added which distinguishes the product from the competition. A new reset pin was introduced to enable controlling the IC externally, the pin has two optional functions which are selected by product version.

Reset version: 

The RST input pin can be controlled by a P-channel open-drain output type and has an internal resistor (RRST) to pull down to Vss.

When the Reset function becomes active (RST pin = VRST > VRDET & tRST timer expires), the IC turns off the charge and discharge control MOSFETs to disconnect the battery from the charger.

As a result, the protection circuits for overcharge, overdischarge, discharge overcurrent, and short circuit are halted and current consumption reduces to a minimum.

The Reset function is released by (RST pin = VRST < VRDET & tRREL timer expires).

Forced-standby version:

The RST input pin can be controlled by a CMOS output type and has an internal resistor (RRST) to pull down to Vss.

When the Forced-Standby function becomes active (RST pin = VRST > VREDT & tRST timer expires), the IC turns off the discharge control MOSFET and pulls the V- pin up to Vdd internally.

As a result, the protection circuits for overcharge, overdischarge, discharge overcurrent, and short circuit are halted and current consumption reduces to a minimum.

The RST pin becomes OPEN when an internal switch is turned off.

The Forced-Standby function is released by connecting a charger. (V- < VRREL & tRREL timer expires)

Traditional current measurement by using the MOSFET on-resistance depends on several specific parameters making the overcurrent threshold less accurate and causes a large margin. A special two-step excess discharge current detector and the use of an external current sense resistor addresses this issue and makes this product ideal for applications that require enhanced safety features. The protection circuit is triggered by two critical excess current thresholds, where the lower threshold has a moderate response speed and the upper threshold a fast response speed.

Additionally, the external current sense resistor value can be in the range of 1.5 mΩ which results in a lower heat dissipation at high currents.

The R5613 has a much lower current consumption compared to predecessor products (2.0 / 2.5 µA) which is especially important for those applications with a small battery capacity.

The IC automatically enter standby mode once the cell voltage drops below a certain threshold, some internal circuits will shut down, reducing current consumption and minimizing further discharge.

Optional functions are available per product version, such as the 0 V battery charging, which offers the option to allow / disallow the battery to recharge from a deep discharged state. Another option is to select between auto-release and latched release from overload conditions.

The R5613 is available in an 8 pins DFN1616-8B package, measuring L1.6 x W1.6 x H0.4 mm. Samples and evaluation boards are available from authorized local distribution channels and online partners Mouser and Digi-Key.

R5613 Features:

Supply Current                                                                           Normal Mode: Typ. 2.5 μA / Max. 4.8 μA

(Only when selected 0 V Battery Charging “Inhibition”

and Discharge Overcurrent Detection with Two-level), Typ. 2.0 μA / Max. 4.0 μA

(Except for the above selection)

Standby Mode:                                                                             Max.0.2 μA (VDET2: Auto Release type)

                                                                                                               Max.0.04 μA (VDET2: Latch type)

Detector Selectable Range and Accuracy

Overcharge detection voltage (VDET1):                                                                  4.2 V to 4.7 V, ±20 mV,

Overdischarge detection voltage (VDET2):                                                              2.1 V to 3.2 V, ±35 mV

Discharge overcurrent detection voltage1 (VDET31):                                      0.0070 V to 0.0300 V, ±1 mV

Discharge overcurrent detection voltage2 (VDET32):                                          0.011 V to 0.060 V, ±2 mV

Charge overcurrent detection voltage (VDET4):                                            -0.0070 V to -0.0300 V, ±1 mV

Short-circuit detection voltage (VSHORT1):                                           0.030 V ≤ Vshort1 ≤ 0.120 V, ±4 mV

                                                                                                         0.120 V < Vshort1 ≤ 0.200 V, ±5 mV

RST Pin Function type selectable:                                                                Reset / Forced-standby type

0 V Battery Charging:                                                                                            Permission / Inhibition

0 V Charge Inhibition Voltage:                                                       1.000 / 1.200 / 1.500 / 2.200 / 2.350 V

Overcharge / Overdischarge Release Voltage Type selectable:                               Auto Release / Latch

Discharge Overcurrent Release Voltage Type selectable:

Auto Release1 (V- = Vdd×0.8 V) / Auto Release2 (V- = 0.1 V) / Latch

Discharge Overcurrent Detection having two-level voltage detection (VDET31/VDET32) selectable: Enable / Disable

Package R5613L                                                                         (L1.6 x W1.6 x H0.4 mm) DFN1616-8B

Datasheet        https://www.n-redc.co.jp/en/pdf/datasheet/r5613-ea.pdf

About Ricoh Electronic Devices Co., Ltd

Ricoh Electronic Devices Co., Ltd is a leading global provider of semiconductor products, offering a comprehensive portfolio of CMOS Power Management and Real Time Clock ICs that enable engineers to design advanced applications for the consumer, industrial and automotive markets. The companies headquarter is based in Japan, as well as development, sales and manufacturing facilities. Regional sales and support offices are located in North America, Europe, and Asia.

Ricoh has an extensive expertise in small package technology and has a focus on developing products providing features such as low-supply current, high-accuracy, high efficiency and high-reliability.

For further information, please visit https://www.n-redc.co.jp/en/ or contact:

RICOH Americas Holding, Inc.
Electronic Devices Division
Tel: (408) 610-3105
Email: edd@ricoh-usa.com

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