SM625/SM626/SM627
SWITCHING REGULATOR POWER OUTPUT STAGES
DESCRIPTION
The SM625/626/627 series of Power Output Stages are espe-
cially designed to be driven with standard PWM integrated
circuits to form an efficient switching power supply. The SM625,
SM626 and SM627 are optimized for non-isolated Buck and
Buck-Boost application. The hybrid circuit construction utilizes
thick film resistors on a beryllia substrate for maximum thermal
conductivity and resultant low thermal impedance. All of the
active elements in the hybrid are fully passivated.
FEATURES
•
Equivalent to the Unitrode PIC 625, 626, 627
•
15A current capability
•
Designed and characterized for switching regulator
applications such as Buck, Boost, and Buck-Boost
type
•
Cost saving design reduces size, improves efficiency,
reduces noise and RFI
•
High operating frequency (to > 100KHz) results in
smaller inductor-capacitor filter and improved power
supply response time
•
High operating efficiency at 7A typical performance -
Rise and fall time < 300ns
Efficiency > 85%
•
Electrically isolated, 4-pin, TO-66 hermetic case
HIGH RELIABILITY FEATURES
♦
Available with high reliability processing
FUNCTIONAL DIAGRAM
SM625/SM626/SM627
4/90 Rev 1.1 2/94
Copyright
©
1994
1
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
SM625/SM626/SM627
ABSOLUTE MAXIMUM RATINGS
(Note 1)
SM625
SM626
SM627
Input Voltage, V
4 - 2
......................................... 60V
80V
100V
80V
100V
Output Voltage, V
1 - 2
...................................... 60V
Drive Input Reverse Voltage, V
3 - 4
................. 5V
5V
5V
15A
15A
Output Current, I
1
.......................................... 15A
Drive Current, I
3
............................................. -0.4A
-0.4A
-0.4A
Thermal Resistance
Operating Junction Temperature
Hermetic (R Package) .................................................. 150°C
Power Switch,
θ
J - C
................................................... 4.0°C/W
Storage Temperature Range ............................. -65°C to 150°C
Commutating Diode .................................................. 4.0°C/W
Lead Temperature (Soldering, 10 Seconds) ....................300°C
Case to Ambient,
θ
C - A
............................................ 60.0°C/W
Note 1. Exceeding these ratings could cause damage to the device.
THERMAL DATA
R Package:
Thermal Resistance-
Junction to Case
,
θ
JC
.................. 4.0°C/W
Thermal Resistance-
Junction to Ambient
,
θ
JA
.............. 40°C/W
Note A. Junction Temperature Calculation: T
J
= T
A
+ (P
D
x
θ
JA
).
Note B. The above numbers for
θ
JC
are maximums for the limiting
thermal resistance of the package in a standard mount-
ing configuration. The
θ
JA
numbers are meant to be
guidelines for the thermal performance of the device/pc-
board system. All of the above assume no ambient
airflow.
RECOMMENDED OPERATING CONDITIONS
(Note 2)
SM625
SM626
Input Voltage, V
4 - 2
......................................... 50V
70V
Output Voltage, V
1 - 2
...................................... 50V
70V
4V
Drive Input Reverse Voltage, V
3 - 4
................. 4V
Output Current, I
1
.......................................... 13A
13A
-0.3A
Drive Current, I
3
............................................. -0.3A
Operating Ambient Temperature Range
SM6XXR ....................................................... 0°C to 70°C
SM6XXHRR ........................................... -55°C to 125°C
Note 2. Range over which the device is functional.
SM627
90V
90V
4V
13A
-0.3A
ELECTRICAL CHARACTERISTICS
(Unless otherwise specified, these specifications apply for the operating ambient temperature of T
A
= 25°C. Low duty cycle pulse testing tech-
niques are used which maintains junction and case temperatures equal to the ambient temperature.)
Parameter
On-State Voltage
(Note 3)
Diode Forward Voltage
(Note 3)
Off-State Current
Diode Reverse Current
Test Conditions
I
4
= 7A(-7A), I
3
= -30mA (30mA)
I
4
= 15A(-15A), I
3
= -30mA (30mA)
I
4
= 7A(-7A)
I
4
= 15A(-15A)
V
4
= Rated input voltage
V
4
= Rated input voltage, T
A
= 125°C
V
1
= Rated output voltage
V
1
= Rated output voltage, T
A
= 125°C
SG625/626/627
Min. Typ. Max.
1.5
1.0
3.5
2.5
0.85 1.25
0.95 1.75
10
0.1
10
10
1.0
500
Units
V
V
V
V
µA
µA
µA
µA
Note 3. Pulse test: Duration = 300µs, Duty Cycle
≤
2%.
4/90 Rev 1.1 2/94
Copyright
©
1994
2
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
SM625/SM626/SM627
ELECTRICAL SPECIFICATIONS
Parameter
(continued)
Test Conditions
SG625/626/627
Min. Typ. Max.
35
65
40
700
70
175
85
60
150
60
175
300
Units
ns
ns
ns
ns
ns
ns
%
Dynamic Characteristics
(See Figures 1 & 2)
(Notes 4 & 5)
Current Delay Time
Current Rise Time
Voltage Rise Time
Voltage Storage Time
Voltage Fall Time
Current Fall Time
Efficiency
(Note 5)
AC TEST CIRCUIT AND SWITCHING TIME WAVEFORMS
(Note 6)
SM625
SM626
SM627
FIGURE 1 - SM625/626/627 SWITCHING SPEED CIRCUIT
FIGURE 2 - SM625/626/627 SWITCHING WAVEFORMS
Note 4. In switching an inductive load, the current will lead the voltage on turn-on and lag the voltage on turn-off (see Figure 2). Therefore, Voltage
Delay Time (t
DV
)
≅
t
di
+ t
ri
and Current Storage Time (t
si
)
≅
t
sv
+ t
fv
.
Note 5. The efficiency is a measure of internal power losses and is equal to Output Power divided by Input Power. The switching speed circuit of Figure
1, in which the efficiency measured, is represenative of typical operating conditions for the SM600 series switching regulators.
APPLICATION CIRCUITS
SM62X
SM62X
FIGURE 3 - STEP DOWN (BUCK) CONVERTER
FIGURE 4 - NEGATIVE OUTPUT DOWN/UP (BUCK-BOOST) CONVERTER
4/90 Rev 1.1 2/94
Copyright
©
1994
3
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
SM625/SM626/SM627
CONNECTION DIAGRAMS & ORDERING INFORMATION
Package
4-PIN TO-66 METAL CAN
R - PACKAGE
(See Note Below)
Part No.
SM625R
SM625HRR
SM626R
SM626HRR
SM627R
SM627HRR
Ambient
Temperature Range
0°C to 70°C
-55°C to 125°C
0°C to 70°C
-55°C to 125°C
0°C to 70°C
-55°C to 125°C
Connection Diagram
POSITIVE OUTPUT
1
2
4
3
POSITIVE INPUT
COMMON
DRIVE
Note 1. All packages are viewed from the top.
2. Case is electrically isolated.
3. Contact factory for additional screening available.
4/90 Rev 1.1 2/94
Copyright
©
1994
4
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
