Memory ICs
Reset IC with battery backup function
BA6129AF / BA6162 / BA6162F
The BA6129AF, BA6162, and BA6162F are reset ICs with a battery backup function, designed for equipment using
SRAMs and other similar components. These ICs are configured of a reset signal and CS signal output unit and a
power supply switching unit. If the BA6129AF detects that the power supply has dropped to 3.5V or lower, it outputs
the CS, CSB, and Reset signals to set the SRAM in backup mode. If the voltage drops to 3.3V or lower, the power
supply switches to the battery. With the BA6162 and BA6162F, in the same way, a power supply of 4.2V is detected,
and if the voltage drops to 3.3V or lower, the power supply switches to the battery. These ICs allow SRAMs to be
write protected and allow the system to be reset, in addition to switching between the power supply and the battery.
Applications
•Equipment
using SRAMs (cards, cassettes, facsimile machines, copiers, word processors, personal computers, etc.)
•1)Features
Equipped with battery backup function.
4) Low voltage loss when powered from battery.
5) Smooth switching between power supply and battery.
2) Equipped with both CS signals (CS and CSB) and
Reset signals.
3) Low current dissipation when powered from battery.
•Absolute maximum ratings (Ta = 25°C)
Symbol
Limits
Unit
Power supply voltage
Parameter
VCC
7.0
V
Output current 1
IOUT1
Output current 2
IOUT2
– 200
µA
Pd
900∗1 (BA6162)
550∗2 (BA6129AF)
mW
Power dissipation
– 80 (BA6129AF)
– 40 (BA6162 / BA6162F)
mA
(BA6162F)
Operating temperature
Topr
– 20 ~ + 75
°C
Storage temperature
Tstg
– 40 ~ + 125
°C
IOUT1 indicates the output current on the VCC side, and IOUT2 the output current on the VBAT side.
∗1 Reduced by 9.0mW for each increase in Ta of 1°C over 25°C.
∗2 Reduced by 5.5mW for each increase in Ta of 1°C over 25°C.
1
Memory ICs
BA6129AF / BA6162 / BA6162F
•Block diagram
VCC
N.C.
Vo
CSB
8
7
6
5
VREF
+
–
+
–
+
–
1
2
3
4
GND
Reset
CS
VBAT
•Pin descriptions
Pin No.
Pin name
1
GND
Substrate GND
Function
2
Reset
Reset output
3
CS
CS output
4
VBAT
Battery power supply
5
CSB
CSB output
6
VO
7
N.C.
8
VCC
Power supply output
—
Power supply voltage
•Input / output circuit
VCC
VCC
VCC
Pin 5
2
6
CSB output
Pin 2
Pin 3
Reset
CS output
output
3
5
Pin 6
Power supply
output
GND
Pin 4
Battery
power supply
8
4
Pin 8
Power supply
(VCC)
Pin 6
Power supply
output
2
GND
GND
6
GND
Memory ICs
BA6129AF / BA6162 / BA6162F
Electrical characteristics
•BA6129AF
(unless otherwise noted, Ta = 25°C, VR
RES
Parameter
No-load current dissipation
= VCC = 5V, RRES = 10kΩ)
Symbol
Min.
Typ.
Max.
Unit
ICC
—
—
2.0
mA
Conditions
VCC = 5V, VBAT = 3V
VSAT1
—
0.03
0.05
V
VCC = 5V, VBAT = 3V, IO = – 1mA
Vo output voltage 1
VO1
4.95
4.97
—
V
VCC = 5V, VBAT = 3V, IO = – 1mA
Vo output voltage 2
VO2
4.70
4.90
—
V
VCC = 5V, VBAT = 3V, IO = – 15mA
I / O voltage differential 1
Vo output voltage 3
VO3
4.50
4.86
—
V
VCC = 5V, VBAT = 3V, IO = – 30mA
Detection voltage
VS
3.35
3.50
3.65
V
VCC = H→L
Detection hysteresis voltage
VSH
—
100
—
mV
Reset output low level voltage
VRESL
—
—
0.4
V
Reset leakage current
IRESH
—
—
0.1
µA
VCC = 5V, VRRES = 7V
Reset operating limit voltage
VOPL
—
0.8
1.2
V
VCC = H→L, VRES ⬉ 0.4V
VCC = L→H
VCC = 3V
CS output low level voltage
VCSL
—
—
0.1
V
VCC = 3V, VBAT = 3V, ICS = + 1µA
CS output high level voltage
VCSH
4.9
—
—
V
VCC = 5V, VBAT = 3V, ICS = – 1µA
—
—
0.1
V
VCC = 5V, VBAT = 3V, ICSB = + 1µA
Vo – 0.1 —
—
V
VCC = 3V, VBAT = 3V, ICSB = – 1µA
CSB output low level voltage
VCSBL
CSB output high level voltage
VCSBH
—
+ 0.05
% / °C
—
Detection voltage temperature characteristic
VS
– 0.05
Switching voltage
VB
3.15
3.30
3.45
V
VCC = H→L, VBAT = 3V, RO = 200kΩ
Switching hysteresis voltage
VBH
—
100
—
mV
VCC = L→H, VBAT = 3V, RO = 200kΩ
Switching voltage temperature characteristic
VB
Backup current dissipation
ICCB
I / O voltage differential 2
– 0.05
—
% / °C
—
—
+ 0.05
—
0.5
µA
VCC = GND, VBAT = 3V
VSAT2
—
0.20
0.30
V
VCC = GND, VBAT = 3V, IO = – 1µA
Vo output voltage 4
VO4
2.70
2.80
—
V
VCC = GND, VBAT = 3V, IO = – 1µA
Vo output voltage 5
VO5
2.60
2.67
—
V
VCC = GND, VBAT = 3V, IO = – 100µA
Vo output voltage 6
VO6
VCC – 0.5
—
—
V
IO = – 80mA
Reverse current
IOR
—
—
0.1
µA
VCC = 5V, VBAT = GND
(Note) IO, ICS, and ICSB are + when flowing toward the pin and – when flowing away from the pin.
䊊 Not designed for radiation resistance.
3
Memory ICs
BA6129AF / BA6162 / BA6162F
BA6162 / F (unless otherwise noted, Ta = 25°C, VRRES = VCC = 5V, RRES = 10kΩ)
Parameter
Symbol
Min.
No-load current dissipation
ICC
—
I / O voltage differential 1
VSAT1
—
Vo output voltage 1
VO1
4.95
Vo output voltage 2
VO2
4.70
Vo output voltage 3
VO3
Detection voltage
Detection hysteresis voltage
Reset output low level voltage
Reset leakage current
Typ.
Max.
Unit
—
2.0
mA
0.03
0.05
V
VCC = 5V, VBAT = 3V, IO = – 1mA
4.97
—
V
VCC = 5V, VBAT = 3V, IO = – 1mA
4.90
—
V
VCC = 5V, VBAT = 3V, IO = – 15mA
4.50
4.86
—
V
VCC = 5V, VBAT = 3V, IO = – 30mA
VS
4.00
4.20
4.40
V
VCC = H→L
VSH
—
100
—
mV
VCC = L→H
VRESL
—
—
0.4
V
VCC = 3.7V
IRESH
—
—
0.1
µA
VCC = 5V, VRRES = 7V
Reset operating limit voltage
VOPL
—
0.8
1.2
V
VCC = H→L, VRES ⬉ 0.4V
CS output low level voltage
VCSL
—
—
0.1
V
VCC = 3.7V, VBAT = 3V, ICS = + 1µA
CS output high level voltage
VCSH
4.9
—
—
V
VCC = 5V, VBAT = 3V, ICS = – 1µA
CSB output low level voltage
VCSBL
—
—
0.1
V
VCC = 5V, VBAT = 3V, ICSB = + 1µA
CSB output high level voltage
VCSBH
—
V
VCC = 3.7V, VBAT = 3V, ICSB = – 1µA
% / °C
—
Vo – 0.1
—
Detection voltage temperature characteristic
KVS
– 0.05
—
Switching voltage
VB
3.15
Switching hysteresis voltage
VBH
—
Switching voltage temperature characteristic
KVB
– 0.05
3.30
100
—
+ 0.05
3.45
—
+ 0.05
VCC = 5V, VBAT = 3V
V
VCC = H→L, VBAT = 3V, RO = 200kΩ
mV
VCC = L→H, VBAT = 3V, RO = 200kΩ
% / °C
—
Backup current dissipation
ICCB
—
—
0.5
µA
VCC = GND, VBAT = 3V
I / O voltage differential 2
VSAT2
—
0.20
0.03
V
VCC = GND, VBAT = 3V, IO = – 1µA
Vo output voltage 4
VO4
2.70
2.80
—
V
VCC = GND, VBAT = 3V, IO = – 1µA
Vo output voltage 5
VO5
2.60
2.67
—
V
VCC = GND, VBAT = 3V, IO = – 100µA
Vo output voltage 6
VO6
VCC – 0.5
—
—
V
IO = – 40mA
Reverse current
IOR
—
—
0.1
µA
VCC = 5V, VBAT = GND
(Note) IO, ICS, and ICSB are + when flowing toward the pin and – when flowing away from the pin.
䊊 Not designed for radiation resistance.
4
Conditions
Memory ICs
BA6129AF / BA6162 / BA6162F
•Measurement circuit
VSAT = VCC – VO
RO 200kΩ VO
IO
V
(VB)
A ICC
VCC
VRRES
8
7
6
5
ICSB
(VS.VB.VOPL)
RRES
VCSB
V
BA6129AF
(BA6162 / F)
10kΩ
3
2
1
4
A
GND
ICCB.IOR
IRES
A
VRES
V
VCS
V
ICS
VBAT
(VOPL) (VS)
Fig. 1
5
Memory ICs
BA6129AF / BA6162 / BA6162F
Circuit operation
•These
ICs have two distinct functions, a logic output function and a power supply switching function.
The logic output circuit consists of the following:
(1) Reset output (NPN Tr open collector)
(2) CS output
(PNP Tr open collector + pull-down resistor)
(3) CSB output (NPN Tr open collector + pull-up resistor)
The power supply switching circuit consists of a PNP
power transistor and an SBD (Schottky barrier diode).
The normal power supply VCC and the battery backup
power supply (VBAT) are both connected to the switching circuit. When the PNP power transistor is turned on
and off, the IC power is switched from the normal
power supply to the battery backup power supply, and
vice versa.
The power supply voltage detection circuit consists of a
standard voltage source VREF and a hysteresis comparator. The power supply VCC is detected using a split
resistance. When the power supply voltage drops
below the detection voltage (BA6129AF: VS = 3.5Vtyp.
when VCC drops and VS + 0.1Vtyp. when VCC rises;
BA6162 / F: VS = 4.2Vtyp. when VCC drops, and VS +
0.1Vtyp. when VCC rises), the Reset signal (Low) and
the CS signal (CS-Low, CSB-High) are output by the
logic output function, and the SRAM (or other memory
device) is switched to backup mode.
If the power supply VCC drops further and goes below
the switching voltage (BA6129AF and BA6162 / F: VB =
3.3Vtyp. when V CC drops, V B + 0.1Vtyp. when V CC
rises), the SBD develops a forward bias because the
PNP power transistor is off. The power supply output
VO switches from the power supply VCC to the battery
power supply (VBAT).
When the normal power supply VCC rises, the above
process is reversed.
(BA6129AF) (BA6162 / F)
5V
VS [3.5VTyp.] [4.2VTyp.]
[3.3VTyp.]
VB
VCC
OV
VO (Vcc) [5V—VSAT1]
VO
VO (BAT) [3V—VSAT2]
OV
VRESH [ⱌ VCC]
RESET
VRESL [ⱌ GND]
VCSH [ⱌ VCC]
CS
VCSL [ⱌ GND]
CSB
VCSBH [ⱌ VO]
VCSBL [ⱌ GND]
Fig. 2 Timing chart
6
Memory ICs
BA6129AF / BA6162 / BA6162F
•Application example
Vcc
5V
SRAM
VDD
C1
10µF
C2
8
7
Vref
6
0.01µF
5
+
–
+
–
R1
10kΩ
+
–
SRAM
CEB
1
2
3
4
SRAM
CE
BATTERY
3V
CPU
Reset
Fig. 3
notes
•(1)Operation
Power supply V
These ICs are designed to operate with at VCC = 5V,
but can also operate at VCC values of other than 5V.
However, the following conditions must be met:
(equation)
(2) Battery voltage VBAT
These ICs are designed to operate with at VBAT = 3V,
but can also operate at VBAT values of other than 3V.
However, the following conditions must be met:
(equation)
{ VV +–VV < <V 5V< V
{ VV
S
CC
SH
BAT
CC
CC
CCMax.
< VB
– VBAT < 5V
BAT
CC
where) VS: detection voltage
VSH: detection hysteresis voltage
VB: switching voltage
7
Memory ICs
BA6129AF / BA6162 / BA6162F
8
VBAT = 3V
RRES = 10kΩ
VRES = VCC
7
6
5
4
3
2
1
0
1
2
3
4
5
6
7
8
9
8
RRES = 10kΩ
VRES = VCC
9
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
0
10
1
2
3
4
5
6
7
8
9
10
0
1
2
3
4
5
6
7
8
9
10
POWER SUPPLY VOLTAGE: VCC (V)
POWER SUPPLY VOLTAGE: VCC (V)
Fig. 4 CS output voltage vs.
power supply voltage
Fig. 5 CSB output voltage vs.
power supply voltage
Fig. 6 Reset output voltage vs.
power supply voltage
5.0
VBAT = 3V
RO = 200kΩ
RRES = 10kΩ
VRES = VCC
OUTPUT VOLTAGE: VO (V)
OUTPUT VOLTAGE: VO (V)
8
10
VBAT = 3V
RRES = 10kΩ
VRES = VCC
9
POWER SUPPLY VOLTAGE: VCC (V)
10
9
10
RESET VOLTAGE: VCSB (V)
9
7
6
5
4
3
2
2.9
VCC = 5V
VBAT = 3V
RRES = 10kΩ
VRES = VCC
4.8
OUTPUT VOLTAGE: VO (V)
CHIP SELECT VOLTAGE: VCS (V)
10
CHIP SELECT BAR VOLTAGE: VCSB (V)
•Electrical characteristic curves (BA6129AF)
4.6
4.4
VCC = GND
VBAT = 3V
RRES = 10kΩ
VRES = VCC
2.8
2.7
1
0
1
2
3
4
5
6
7
8
9
4.2
0
10
20
40
60
80
2.6
0
100
50
100
150
200
250
POWER SUPPLY VOLTAGE: VCC (V)
OUTPUT CURRENT: IO (mA)
OUTPUT CURRENT: IO (µA)
Fig. 7 Output voltage vs. power
supply voltage
Fig. 8 Output voltage vs. output
current (!) (when power
supply is detected)
Fig. 9 Output voltage vs. output
current (@) (when using
battery backup)
•Electrical characteristic curves (BA6162 / F)
7
6
5
4
3
2
1
0
8
1
2
3
4
5
6
7
8
9
10
9
8
10
VBAT = 3V
RRES = 10kΩ
VRES = VCC
9
RESET VOLTAGE: VRES (V)
VBAT = 3V
9 RRES = 10kΩ
VRES = VCC
8
CHIP SERECT BAR VOLTAGE: VCSB (V)
CHIP SELECT VOLTAGE: VCS (V)
10
7
6
5
4
3
2
1
0
RRES = 10kΩ
VRES = VCC
8
7
6
5
4
3
2
1
1
2
3
4
5
6
7
8
9
10
0
1
2
3
4
5
6
7
8
9
10
POWER SUPPLY VOLTAGE: VCC (V)
POWER SUPPLY VOLTAGE: VCC (V)
POWER SUPPLY VOLTAGE: VCC (V)
Fig. 10 CS output voltage vs.
power supply voltage
Fig. 11 CSB output voltage vs.
power supply voltage
Fig. 12 Reset output voltage vs.
power supply voltage
Memory ICs
BA6129AF / BA6162 / BA6162F
10
5.0
7
6
5
4
3
2
2.9
VCC = 5V
VBAT = 3V
RRES = 10kΩ
VRES = VCC
OUTPUT VOLTAGE: VO (V)
OUTPUT VOLTAGE: VO (V)
8
OUTPUT VOLTAGE: VO (V)
VBAT = 3V
RO = 200kΩ
RRES = 10kΩ
VRES = VCC
9
4.9
4.8
1
0
1
2
3
4
5
6
7
8
9
10
4.7
0
10
20
30
40
VCC = GND
VBAT = 3V
RRES = 10kΩ
VRES = VCC
2.8
2.7
2.6
0
50
50
100
150
200
250
POWER SUPPLY VOLTAGE: VCC (V)
OUTPUT CURRENT: IO (mA)
OUTPUT CURRENT: IO (µA)
Fig. 13 Output voltage vs. power
supply voltage
Fig. 14 Output voltage vs. output
current (!) (when power
supply is detected)
Fig. 15 Output voltage vs. output
current (@) (when using
battery backup)
•External dimensions (Units: mm)
BA6129AF, BA6162F
BA6162
9.3 ± 0.3
5.0 ± 0.2
5
1
4
0.4 ± 0.1
0.3Min.
7.62
0.51Min.
0.15 ± 0.1
4
3.2 ± 0.2 3.4 ± 0.3
0.11
1.27
8
6.5 ± 0.3
5
4.4 ± 0.2
1
1.5 ± 0.1
6.2 ± 0.3
8
0.3 ± 0.1
2.54
0.5 ± 0.1
0°~15°
0.15
SOP8
DIP8
9