MITSUBISHI M62212P

MITSUBISHI SEMICONDUCTORS <Standard Linear ICs>
M62212P/FP/GP
GENERAL PURPOSE DC-DC CONVERTER
DESCRIPTION
PIN CONFIGURATION(TOP VIEW)
Collector
output 1
Emitter 2
output
FEATURE
GND
3
Cosc
4
• Wide operation power supply voltage range •••••••2.5 ~ 18V
• Low power consumption••••••••••••••••••••••••1.3mA typ
• High speed switching is possible.(300kHz)
• Output short protection circuit and ON/OFF control are used.
The dead-time control and the soft-start operation are
possible
• Package variation : 8pin DIP/SOP/SSOP8
M62212P /
FP / GP
M62212 is designed as a general purpose DC-DC converter.
This small 8 pin package contains many functions allowing
simpler peripheral circuits and compact set design.
The output transistor is open collector and emitter follower
type. This makes the control STEP-UP,STEP-DOWN and
INVERTING converter.
8
VCC
7
IN
6
FB
5
DTC
OUTLINE 8P2S-A (FP)
8P2X (GP)
8P4 (P)
APPLICATIONS
General electric products, DC-DC converter
BLOCK DIAGRAM
VCC
8
UVLO
VTH : 2.3V
PWM Comp
OSC
COSC 4
VCC
OP Amp
Short protection
circuit
1.25V
IN 7
VCC
1.86V
1.25V
R
S Q
1.15V
6
FB
5
DTC
(1/8)
3
GND
0.3V
1
Collector
output
2
Emitter
output
MITSUBISHI SEMICONDUCTORS <Standard Linear ICs>
M62212P/FP/GP
GENERAL PURPOSE DC-DC CONVERTER
ABSOLUTE MAXIMUM RATINGS (Ta=25°C, unless otherwise noted)
Symbols
Items
Conditions
Ratings
Units
Vcc
Power supply voltage
19
V
Vo
Output voltage
19
V
Io
Output current
150
mA
Pd
Power dissipation
Ta=25°C
625 (P) 360(FP) 250(GP)
mW
Ktheta
Thermal derating ratio
Ta>25°C
Topr
Operating ambient temperature
Tstg
Storage temperature
5.00 (P) 2.88 (FP) 2.00(GP) mW/°C
-20°C ~ +85
°C
-40°C ~ +125
°C
Electrical Characteristics ( Ta=25°C, Vcc =12V, Cosc=100pF unless otherwise noted )
Block
Symbol
All
device
VCC
Range of power supply voltage
I CC ST
Standby current
Output "OFF" status
Std.
voltage
section
V REF
Standard voltage
Voltage follower
L INE
Line regulation
VCC=2.5 ~ 18V
IB
Input bias current
AV
Open loop gain
Error
amp.
section
GB
VOM
VOM
-
I OM
+
-
f OSC
Oscillator
section
UVLO
section
Test condition
Limits
Min
Typ
1.19
1.3
1.8
mA
1.25
1.31
V
5
12
mV
500
nA
80
dB
0.6
MHz
Output low voltage
Output sink current
VFB=1.86V
Output source current
VIN =1V
2.62
V
400
mV
mA
6
-60
Oscillation frequency
Units
V
1.82
Output high voltage
Max
18
2.5
Unity gain bandwidth
+
I OM
Items
-30
uA
110
kHz
VOSCH
Upper limit voltage of oscillation waveform
1.0
V
VOSCL
Lower limit voltage of oscillation waveform
0.45
V
I OSC CH
Cosc charge current
-40
uA
I OSC DIS1
Cosc discharge current 1
10
uA
VTH ON
Start-up threshold voltage
VIN =1V
VTH OFF
Shut-down threshold voltage
VIN =1V
VHYS
Hysteresis
VHYS = VTHON - VTHOFF
(2/8)
2.2
2.3
2.4
V
2.25
20
50
V
80
mV
MITSUBISHI SEMICONDUCTORS <Standard Linear ICs>
M62212P/FP/GP
GENERAL PURPOSE DC-DC CONVERTER
Electrical Characteristics ( Ta=25°C, Vcc =12V, Cosc=100pF unless otherwise noted )
Block
Short
protection
circuit
Symbol
Test condition
Limits
Min
Typ
Max
Units
VTH FB
FB threshold voltage
VIN =1V,VDTC=0.7V
1.86
V
VTH DTC
Latch mode "H" threshold voltage
VIN =1V,VFB =2.11V
1.15
V
VTL DTC
Latch mode "L" threshold voltage
VIN =1V,VFB =2.11V
0.3
V
I CH1
DTC charge current when start-up
VDTC=0.7V,VFB =2.11V
-45
µA
I DIS1
DTC discharge current 1
VDTC=0.7V,VFB =2.11V
50
µA
I CH2
DTC charge current when stable state VDTC=0.7V,VFB = 0.7V
-10
µA
I DIS2
DTC discharge current 2
VDTC=0.2V,VFB =2.11V
15
µA
Collector output leak current
VCE=18V , VCC=18V
I CL
Output
section
Items
VSAT1
Collector output saturation voltage 1
VSAT2
Collector output saturation voltage 2
Emitter GND,
IC=150mA,VE=0V
Emitter follower,
IE=50mA,VC=12V
(3/8)
-1
0.3
1.6
1
µA
1.1
V
V
MITSUBISHI SEMICONDUCTORS <Standard Linear ICs>
M62212P/FP/GP
GENERAL PURPOSE DC-DC CONVERTER
1. Application Circuit (STEP-DOWN converter with current buffer transistor)
L
VIN
VOUT
D
CIN
R1
8
1
R2
4
COSC
M62212
2
7
6
5
3
(4/8)
COUT
MITSUBISHI SEMICONDUCTORS <Standard Linear ICs>
M62212P/FP/GP
GENERAL PURPOSE DC-DC CONVERTER
2. FUNCTION DESCRIPION
1) Soft Start (The peripheral circuit is shown in Fig.1)
When the power is turned ON, input terminal IN is at 0V level. Therefore, the FB
terminal is fixed to High level. The DTC terminal goes up gradually starting from 0V
due to the internal charge current and the external CDTC.
When the level of DTC terminal reaches the lower limit of the triangular wave of the
oscillator, PWM comparator and the output circuit go into operation causing the output
voltage, "Vo" of the DC-DC converter to rise. The charge current is designed to be
approximately 45µA.
FB
DTC
1.0V
OSC
0.45V
OFF
External Tr collector
ON
Fig.2
2) DTC
The dead time control is set by installing a resistor between the DTC terminal and GND.
However, the DTC terminal serves as the short protection circuit also. Therefore, its set up
depends on whether the short protection circuit is used and not.
(When the short protection circuit is used)
At this time, the charge current for DTC is approximately 10µA . Therefore, RDTC should
be set to 40KΩ ~ 110KΩ.
(When the short protection circuit is not used)
At this time, the charge current for DTC is approximately 45µA. Therefore, RDTC is set to
12KΩÅ`25KΩ.
(5/8)
MITSUBISHI SEMICONDUCTORS <Standard Linear ICs>
M62212P/FP/GP
GENERAL PURPOSE DC-DC CONVERTER
3) Short Protection Circuit
The Short Protection Circuit used the timer latch system. It is determined by setting the
capacity used for the soft start connected to the DTC terminal.
Fig.3 shows the short protection circuit and the timing chart for various modes.
When the power is turned on, the FB terminal goes high (approx. 2.3V) and the DTC
terminal goes low (goes up slowly from 0V). Thus, approximately 45µA current will flow
when SW1:ON and SW2:OFF. The potential, namely the potential of the FB terminal is in
the amplitude of the triangular wave, SW1 will be OFF and SW2 will be ON and approximately
50µA will flow into the DTC terminal. This discharge current will cause the DTC terminal to
drop from 1.15V.
At this time, if the potential of the FB terminal goes to the control potential before the
potential at the DTC terminal goes lower than 0.45V which is the lower limit value of the
triangular wave and if the potential of the FB terminal is lower than the potential of the DTC
terminal, then the system is activated.
When the output is shorted, the system is either activated or latched depending on
whether the time for the high potential of the FB terminal reaches the potential of the control
state is long or short. (For detail, see [II] and [IV] of the Mode)
There are two ways to go back to operation after the latch to shut off output. Either
method can restart with soft start.
1. Turning ON the Vcc.
2. Make the FB terminal to go to the low potential of 1.86V or less. Then, it is
cancel led.
[Mode Explained]
[ I ] Mode •••••••••••• Activation
This is used when the FB terminal goes down to the control state potential when the DTC
terminal is in up slope. In order for the activation to occur when the DTC terminal is in down
slope, the FB terminal potential must go below the DTC terminal before the DTC terminal
goes to 0.45V.
[ II ] Mode ••••••••••••• Output short --> Activation
The system is activated if the FB terminal potential goes below the DTC terminal potential
before the DTC terminal goes to 0.45V. If there is not enough time, the output is turned OFF
(Latched)
[ III ] Mode •••••••••••• ON/OFF Control --> Activation
This mode turns off the output by forcing the DTC terminal to go down. (The system)
returns as in the case of the activation.
[ IV ] Mode •••••••••••• Output Short (Latch)
The output is turned OFF when the FB terminal potential did not go down to the control
state before the DTC terminal went down to 0.45V.
(6/8)
MITSUBISHI SEMICONDUCTORS <Standard Linear ICs>
M62212P/FP/GP
GENERAL PURPOSE DC-DC CONVERTER
Comp1
FB
(Initial RESET)
1.86V
R
Q
Vcc
1.25V
I2
35µ
I1
10µ
S
SW1
DTC
CDTC
Comp2
I3
60µ
RDTC
90KΩ
(900mV)
1.15V
0.3V
SW2
* SW1 and SW2 are turned ON by "H" signal.
FB
2.0
1.15
DTC
DTC set up value (Tentative)
1.0
OSC
0.45
0
I1
I2
I3
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
OFF
OFF
OFF
OFF
ON
ON
OFF
OFF
OFF
ON
OFF
ON
OFF
ON
OFF
OFF
OFF
ON
OFF
ON
ON
Charge Discharge
45µ
50µ
Charge
10µ
Discharge
50µ
Charge
10µ
Charge Charge Discharge
45µ
45µ
50µ
Charge
10µ
Discharge Discharge
50µ
15µ
Activate
Output short
ON/OFF control --> Activate
Output short (Latch)
[I]
[ II ]
[ III ]
[ IV ]
Fig.3 Short Protection Circuit and the Timing Chart of the Modes
(7/8)
MITSUBISHI SEMICONDUCTORS <Standard Linear ICs>
M62212P/FP/GP
GENERAL PURPOSE DC-DC CONVERTER
3.CONSTANT DEFINITION
CONSTANT
TON
TOFF
TON + TOFF
TOFF (MIN)
TON (MAX)
D (MAX)
COSC
L (MIN)
R1
RDTC
(*1,*2)
not use short
protection
use short
protection
(*4)
CDTC
(*4)
(*1)
calicurate from
start-up time
calicurate from
shat down time
Step-down converter
Step-up converter
VO + VF
VIN - VCE(sat) - VO
1
fOSC
VO + VF - VIN
VIN - VCE(sat)
1
fOSC
TON + TOFF
TON
1+
TOFF
Inverting converter
|Vo| + VF
VIN - VCE(sat)
1
fOSC
TON + TOFF
TON
1+
TOFF
1
-TOFF
fOSC
1
-TOFF
fOSC
TON + TOFF
TON
1+
TOFF
1
-TOFF
fOSC
TON(MAX)
TON(MAX)
TON(MAX)
TON + TOFF
TON + TOFF
TON + TOFF
1
1
1
-16 * 10 -12
-16 * 10 -12
-16 * 10 -12
3
3
75 * 10 * fosc
75 * 10 * fosc
75 * 10 3 * fosc
2
2
2
2
(VIN - VCE(sat) - VO) * TON(MAX) (VIN -VCE(sat)) * TON(MAX) * fOSC (VIN -VCE(sat)) * TON(MAX) * fOSC
2 * V O * IO
2 * V O * IO
∆IO
VO
-1 * R2
VREF
VDTC(MAX)
| ICH1 |
VDTC(MAX)
| ICH2 |
| ICH1 | * tstart
VDTC(MAX)
IDIS1 * tshort
VDTC(MAX) -VOSCL
VO
-1 * R2
VREF
VDTC(MAX)
| ICH1 |
VDTC(MAX)
| ICH2 |
|VO|
-1
*R2
VREF
VDTC(MAX)
| ICH1 |
VDTC(MAX)
| ICH2 |
| ICH1 | * tstart
VDTC(MAX)
IDIS1 * tshort
VDTC(MAX) -VOSCL
| ICH1 | * tstart
VDTC(MAX)
IDIS1 * tshort
VDTC(MAX) -VOSCL
VF : Forward Voltage of outer Diode.
VCE(sat) : Saturation Voltage of M62212 or Saturation Voltage of Current buffer Transistor.
Åô Please setting the Oscillation frequency first and calicurate each constant value.
*1 : Please setting ŢIo about 1/3 to 1/5 of maximum output current.
R1
*2 :|Vo|= (1+
) * VREF
R2
*3 : Please settng R2 about few KÉ∂ to score of KÉ∂ because output voltage don't
undergo
a influence of input current (Terminla 7).
*4 : Please setting VDTC(MAX) to satisfy D(MAX), fixed from caracteristics of D(MAX) - VDTC(MAX).
ICH1 means DTC charge current when start-up(-45µA typ), ICH2 means DTC charge current
when stable state(-10µA typ), VOSCL means lower limit vlage of oscillation waveform
(0.45V typ), and IDIS1 means DTC discharge current 1(50µA typ).
tstart means time internval when terminal vltage of DTC increase to VOSCL from lower voltage
and to start switching at first.
tshort means time interval when output is shut down after output is shorted.
(8/8)