RICOH R5421N111C-TR, R5421N112C-TR, R5421N151F-TR, R5421N152F-TR Datasheet

’99.9.21

Li-Ion BATTERY PROTECTOR

R5421NxxxC/xxxF series

■ OUTLINE

The R5421NxxxC/F Series are protection ICs for over-charge/discharge of rechargeable one-cell Lithium-ion (Li+) excess load current, further include a short circuit protector for preventing large external short circuit current.

Each of these ICs is composed of three voltage detectors, a reference unit, a delay circuit, a short circuit protector, and a logic circuit. When charging voltage crosses the detector threshold from a low value to a value higher than VDET1, the output of COUT pin, the output of over-charge detector/VD1, switches to low level, charger's negative pin level. After detecting over-charge the VD1 can be reset and the output of COUT becomes high when the VDD voltage is coming down to a level lower than “V REL1”, or when a kind of loading is connected to VDD after a charger is disconnected from the battery pack while the VDD level is in between “V DET1” and “V REL1” in the R5421NxxxC/F version.

The output of DOUT pin, the output of over-discharge detector/VD2, switches to low level after internally fixed delay time passed, when discharging voltage crosses the detector threshold from a high value to a value lower than VDET2.

After R5421NxxxC/F Series detect the over-discharge voltage, connect a charger to the battery pack, and when the battery supply voltage becomes higher than the over-discharge detector threshold, VD2 is released and the voltage of DOUT becomes “H” level. In the case of F version, after detecting the over-discharge detection, when the battery supply voltage becomes equal or higher than over-discharge released voltage, VD2 is also released by the condition, and the voltage of DOUT becomes “H” level.

An excess load current can be sensed and cut off after internally fixed delay time passed through the built in excess current detector, VD3, with DOUT being enabled to low level. Once after detecting excess current, the VD3 is released and DOUT level switches to high by detaching a battery pack from a load system.

Further, short circuit protector makes DOUT level to low immediately with external short circuit current and removing external short circuit leads DOUT level to high. After detecting over-discharge, supply current will be kept extremely low by halt some internal circuits operation. The output delay of over-charge detectors can be set by connecting external capacitors. Output type of COUT and DOUT are CMOS. 6-pin, SOT23-6 is available.

■ FEATURES

	Low supply current....................................................	Supply current		Typ. 3.0µA
		Standby current (detecting over-discharge)		Typ. 0.3µA
				(for R5421NxxxC)
				Typ. 1.0µA
				(for R5421NxxxF)
High accuracy detector threshold ..............................		Over-charge detector (Topt=25°C)		±25mV
		(Topt=0 to 50°C)		±30 mV
		Over-discharge detector		±2.5%
	Variety of detector threshold .....................................	Over-charge detector threshold	4.0V - 4.4V step of 0.005V
		Over-discharge detector threshold	2.0V - 3.0V step of 0.005V
	Built-in protection circuit ..........................................	Excess current protection	0.05V - 0.4V step of 0.005V
		Accuracy		±15%
Output delay of over-charge ......................................		Time delay at C3=0.01µF and V DD=4.3V
			75ms for R5421N111C
	Output delay of over-discharge .................................	VDD=2.4V with built-in capacitor
			10ms for R5421N111C/112C
	Small package............................................................	SOT-23-6 / 6-pin

■ APPLICATIONS

Li+ one-cell protector for battery pack

High precision protectors for cell-phones and any other gadgets using on board Li+ one-cell battery

Rev.1.11	- 1 -

■ BLOCK DIAGRAM

R5421NxxxC

VDD	Ct
5	4

Level

Shifter

VD1

			Short circuit
		Delay	Detector
		VD2
		VD3
	6	1	3	2
	VSS	DOUT	COUT	V-
	R5421NxxxF
	VDD	Ct
	5	4

	Level
	Shifter
VD1
	Short circuit
Delay	Detector
VD2

VD3

6	1	3	2
VSS	DOUT	COUT	V-

Rev.1.11		- 2 -

■ SELECTION GUIDE

In the R5421Nxxxx Series three of the input threshold for over-charge, over-discharge and excess current detectors can be designated.

Part Number is designated as follows:

R5421N XXXX-XX ←Part Number

− − −

a b c

	Code	Description
	a	Serial Number for the R5421N Series designating input threshold for over-charge, over-discharge
		and excess current detectors as well as hysteresis range for over-charge detector.
	b	Designation of version symbols
	c	Taping Type: TR (refer to Taping Specification)

■ PIN CONFIGURATION

6

5

4

(mark side)

1

2

3

■ PIN DESCRIPTION

	Pin No.	Symbol	Pin description
	1	DOUT	Output of over-discharge
			detection, CMOS output
	2	V-	Pin for charger negative input
	3	COUT	Output of over-charge
			detection, CMOS output
	4	Ct	Pin for external capacitor
			setting output delay of VD1
	5	VDD	Power supply
	6	VSS	Ground

Rev.1.11

- 3 -

■ ABSOLUTE MAXIMUM RATINGS

				VSS=0V
	Symbol	Item	Ratings	Unit
	VDD	Supply voltage	-0.3 to 12	V
		Input Voltage
	V-	V - pin	VDD -28 to VDD +0.3	V
	VCt	Ct pin	VSS -0.3 to VDD +0.3	V
		Output voltage
	VCOUT	COUT pin	VDD -28 to VDD +0.3	V
	VDOUT	DOUT pin	VSS -0.3 to VDD +0.3	V
	PD	Power dissipation	150	mW
	Topt	Operating temperature	-40 to 85	°C
		range
	Tstg	Storage temperature range	-55 to 125	°C

ABSOLUTE MAXIMUM RATINGS

Absolute Maximum ratings are threshold limit values that must not be exceeded ever for an instant under any conditions. Moreover, such values for any two items must not be reached simultaneously. Operation above these absolute maximum ratings may cause degradation or permanent damage to the device. These are stress ratings only and do not necessarily imply functional operation below these limits.

Rev.1.11		- 4 -

■ ELECTRICAL CHARACTERISTIC

	● R5421N111C						Topt=25°C
	Symbol	Item	Conditions	MIN.	TYP.	MAX.	Unit
	VDD1	Operating input voltage	Voltage defined as VDD - VSS	1.5		10	V
	Vst	Minimum operating	Voltage defined as VDD - V- ,			1.2	V
		Voltage for 0V charging	VDD - VSS=0V
	VDET1	Over-charge threshold	Detect rising edge of supply
			voltage
			(Topt=25°C)	4.225	4.250	4.275	V
			(Topt=0 to 50°C) *Note	4.220	4.250	4.280	V
	VREL1	Release voltage for over-		4.00	4.05	4.10	V
		charge detection
	tVDET1	Output delay of over-	C3=0.01µF, V DD=3.6V to 4.3V	60	75	90	ms
		Charge
	VDET2	Over-discharge threshold	Detect falling edge of supply	2.437	2.500	2.563	V
			voltage
	tVDET2	Output delay of over-	VDD=3.6V to 2.4V	7	10	13	ms
		Discharge
	VDET3	Excess current threshold	Detect rising edge of 'V-' pin	0.17	0.20	0.23	V
			voltage
	tVDET3	Output delay of excess	VDD=3.0V	9	13	17	ms
		Current
	Vshort	Short protection voltage	VDD=3.0V	VDD-1.2	VDD-0.9	VDD-0.6	V
	tshort	Output Delay of Short	VDD=3.0V		5	50	µs
		protection
	Rshort	Reset resistance for Excess	VDD=3.6V, V- =1.0V	50	100	150	kΩ
		current protection
	Vol1	Nch ON voltage of COUT	Iol=50µA, V DD=4.4V		0.35	0.5	V
	Voh1	Pch ON voltage of COUT	Ioh=-50µA, V DD=3.9V	3.4	3.7		V
	Vol2	Nch ON voltage of DOUT	Iol=50µA, V DD=2.4V		0.2	0.5	V
	Voh2	Pch ON voltage of DOUT	Ioh=-50µA, V DD=3.9V	3.4	3.7		V
	IDD	Supply current	VDD=3.9V, V- =0V		3.0	6.0	µA
	Istandby	Standby current	VDD=2.0V		0.3	0.6	µA

*Note: Considering of variation in process parameters, we compensate for this characteristic related to temperature by lasertrim, however, this specification is guaranteed by design, not production tested.

Rev.1.11	- 5 -

	● R5421N112C						Topt=25°C
	Symbol	Item	Conditions	MIN.	TYP.	MAX.	Unit
	VDD1	Operating input voltage	Voltage defined as VDD - VSS	1.5		10	V
	Vst	Minimum operating	Voltage defined as VDD - V- ,			1.2	V
		Voltage for 0V charging	VDD - VSS=0V
	VDET1	Over-charge threshold	Detect rising edge of supply
			Voltage
			Topt=25°C	4.325	4.350	4.375	V
			Topt=0 to 50°C *Note	4.320	4.350	4.380	V
	VREL1	Release voltage for over-		4.100	4.150	4.200	V
		charge detection
	tVDET1	Output delay of over-	C3=0.01µF, V DD=3.6V to 4.4V	61	77	93	ms
		Charge
	VDET2	Over-discharge threshold	Detect falling edge of supply	2.437	2.500	2.563	V
			Voltage
	tVDET2	Output delay of over-	VDD=3.6V to 2.4V	7	10	13	ms
		Discharge
	VDET3	Excess current threshold	Detect rising edge of 'V-' pin	0.17	0.20	0.23	V
			Voltage
	tVDET3	Output delay of excess	VDD=3.0V	9	13	17	ms
		Current
	Vshort	Short protection voltage	VDD=3.0V	VDD-1.2	VDD-0.9	VDD-0.6	V
	tshort	Output Delay of Short	VDD=3.0V		5	50	µs
		protection
	Rshort	Reset resistance for excess	VDD=3.6V, V- =1.0V	50	100	150	kΩ
		current protection
	Vol1	Nch ON voltage of COUT	Iol=50µA, V DD=4.4V		0.35	0.5	V
	Voh1	Pch ON voltage of COUT	Ioh=-50µA, V DD=3.9V	3.4	3.7		V
	Vol2	Nch ON voltage of DOUT	Iol=50µA, V DD=2.4V		0.2	0.5	V
	Voh2	Pch ON voltage of DOUT	Ioh=-50µA, V DD=3.9V	3.4	3.7		V
	IDD	Supply current	VDD=3.9V,V- =0V		3.0	6.0	µA
	Istandby	Standby current	VDD=2.0V		0.3	0.6	µA

*Note: Considering of variation in process parameters, we compensate for this characteristic related to temperature by lasertrim, however this specification is guaranteed by design, not production tested.

Rev.1.11		- 6 -