Rohm BD7679G Pwm current mode method Datasheet

Datasheet
PWM Control Type
DC/DC Converter IC for AC/DC Driver
BD7679G
●General Description
BD7679G is a PWM controller type DC/DC converter
IC for AC/DC that provides an optimum system for all
products that requires an electrical outlet. This product
supports both isolated and non-isolated devices. IC
enables simple design of low-power electrical
converters. With switching MOSFET and current
detection resistor as external devices, it enables more
freedom in design.
Since the peak current control is utilized, peak current
is controlled in each cycles, application excels wide
bandwidth and transient response.
BD7679G includes various protective functions such
as soft start function, burst function, per-cycle over
current limiter, VCC overvoltage protection and
overload protection.
An external stop pin (COMP pin) is provided, so that
switching stopping can be set by external signals. The
function is available as overheating protection and over
voltage protection of secondary output, so on.
The PWM switching frequency is fixed at 65 kHz.
A frequency hopping function is included which contributes
to low EMI.
●Features
■ PWM frequency of 65kHz
■ PWM current mode method
■ Low circuit current when UVLO is ON
(12μA at VCC=12V)
■ Low circuit current without load
(Burst operation when load is light)
■ Built-in SW frequency hopping function
■ 250ns leading-edge blanking
■ VCC UVLO / OVP (Auto restart)
■ Per-cycle over current protection circuit
■ Soft start
■ Output overload protection(Auto-restart protection)
■ External stop function for COMP pin (Auto restart)
●Key Specifications
 Power Supply Voltage range:
8.5V to 25.0V
 Operating Current:
Normal:
0.60mA (Typ)
Burst:
0.40mA (Typ)
 Oscillation Frequency:
65kHz (Typ)
 Operating Temperature range:
-40°C to +85°C
●Package
SSOP6
W(Typ) x D (Typ) x H (Max)
2.90mm x 2.80mm x1.25mm
●Applications
AC adapters and household appliances (vacuum cleaners,
humidifiers, air cleaners, air conditioners, refrigerators, IH
cooking heaters, rice cookers, etc.)
●Typical Application Circuit
Figure 1,
○Product structure：Silicon monolithic integrated circuit
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Application Diagram (Isolated type)
○This product is not designed protection against radioactive rays
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Datasheet
BD7679G
79
●Pin Configuration（SSOP6）
(Unit:mm)
Figure 2,
External Dimensions of SSOP6 Package
●Pin Description
Table 1 I/O PIN Functions
NO.
Pin Name
I/O
1
GND
I/O
2
FB
3
4
ESD protection system
Function
VCC
GND
GND pin
○
-
I
Feedback signal input pin
○
○
COMP
I
Comparator input pin
○
○
CS
I
Primary current sensor pin
○
○
5
VCC
I
Power supply input pin
-
○
6
OUT
O
External MOS drive pin
○
○
●I/O Equivalent Circuit
1
GND
2
FB
3
VREF
GND
COMP
VREF
20kΩ
FB
4
CS
5
VCC
6
OUT
VCC
VREF
VCC
CS
OUT
Figure 3, I/O Equivalent Circuit
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Datasheet
BD7679G
●Block Diagram
+
FUSE
AC
Diode
Bridge
Filter
85- 265Vac
-
+
-
VCC UVLO
13.5V / 7.5V
+
-
4.0V
LineReg
Internal Block
4.0V LineReg
VCC OVP
Auto Restart
(27.5V)
Soft Start
0～1msec Maxduty 15%
1～8msec Maxduty 25%
+
2.0V
S
4.0V LineReg
PWM Control
R
DRIVER
Q
20kΩ
OLP
Comparator
+
Timer
250ms
+
-
Leading Edge
Blanking
(typ=250ns)
Current Limit
Comparator
Pulse Skip
Comparator
+
PWM
Comparator
-
MAX
DUTY
+
Frequency
hopping
+
OSC = 65 kHz
Slope
Compensation
FeedBack
With
Isolation
Figure 4, Block Diagram
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Datasheet
BD7679G
●Description of Each Block
( 1 ) Start Sequences (Soft Start Operation, Light Load Operation, and Overload Protection)
Start sequences are shown in Figure 5. This is also shown the operation of overload protection.
See the sections below for detailed descriptions
VH
VCC=13.5V
VCC＝7.5V
VCC＝7.0V
VCC
Within
250ms
Internal REF
Pull Up
250ms
FB
Over Load
Vout
Normal Load
Light LOAD
Iout
Burst mode
Switching
stop
Switing
Switching
Soft Start
A
BC
D
E
F
G H
I
J
Figure 5, Start Sequence Timing Chart
A: Input voltage VH is applied
B: VCC pin voltage rises by being supplied from VH line through start resistor “Rstart” and the IC starts operating when VCC >
VUVLO1 (13.5V Typ).
Switching operation starts when other protection functions are judged as normal.
From startup to be stable output voltage, application should be set to stabilize output voltage during VCC > VUVLO2 (7.5V Typ)
because the VCC pin consumption current causes the VCC voltage drop.
C: Operated soft start function, maximum duty is restricted to 15% during a 1ms period to prevent any excessive rise in voltage
or current. From 1ms to 8ms, maximum duty is restricted to 25%. Maximum duty is restricted to 75% after 8ms.
D: VOUT voltage rises when the switching operation starts.
Once the output voltage starts, it is set to the rated voltage level within the TFOLP period (250ms Typ).
The output voltage is regulated within TFOLP (=250ms Typ) from starting.
E: During Light Load, when FB pin voltage < VBST (=0.3V Typ), Burst method is operated to keep power consumption down.
F: Over Load condition occurs when FB pin voltage > VFOLP1A (=3.6V Typ).
G: When FB pin voltage is at VFOLP1A (= 3.6V Typ) for more than TFOLP (250ms Typ), the overload protection function is triggered
and switching is stopped. The IC’s internal 250ms timer is reset during the TFOLP period (250ms Typ) if FB < VFOLP1B even
once.
H: If the VCC voltage drops to VUVLO2 (7.5Vtyp) or below, restart is executed.
I: The IC’s circuit current is reduced and the VCC pin value rises. (Same as B).
J: Same as D
In Figure 4, start resistor Rstart is needed to start the application.
When the start resistor Rstart value is reduced, standby power is increased and the startup time is shortened.
Conversely, when the start resistor Rstart value is increased, standby power is reduced and the startup time is lengthened.
Standby current is less than 20uA at VCC UVLO is disable, and it can calculate VCC UVLO voltage from VUVLO1=14.5V
(Max).
ex） Starting resistor Rstart setting method;
Rstart = (VHmin - VUVLO1（Max）) / IOFF（Max）
In the case of Vac=100V (-20% of a margin), Rstart requirement can be found by the following formulas:
VHmin =100 × √2 × 0.8 = 113V
Because of VUVLO1 (Max) =14.5V, Rstart ≦ (113V - 14.5V) / 20μA＝4.975MΩ
Start-up time can be found by the following formulas:
Tstart = -Rstart × CVCC × ln (1-VUVLO1/VHmin)
ex）Rstart=3.0MΩ
2
2
Rstart resistor loss in this case is : Pd (Rstart) = (VH-VCC) / Rstart = (141V - 14.5V) / 3.0M = 5.35mW.
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Datasheet
BD7679G
( 2 ) VCC Pin Protection
BD7679G includes UVLO (Under Voltage Locked Out) and OVP (Over Voltage Protection) functions to monitor VCC pin
voltage (see Figure 6 for OVP auto-restart operation).
The UVLO function prevents damage to MOSFET by stopping switching operations when the VCC pin voltage drops to VCC
< VUVLO2 (= 7.5V Typ).
The VCC OVP function prevents damage to MOSFET by stopping switching operations when the VCC pin voltage exceeds
VOVP1 (= 27.5V Typ). Once the switching is stopped, IC stops switching until VCC < VOVP2(=22.5V Typ).
A blanking time of TSTOP(=100us.Typ) is prepared for protecting mal-function.
VCC
27.5V
22.5V
13.5V
7.5V
Time
SW
ON
ON
OFF
ON
OFF
Time
Figure 6, VCC UVLO/OVP Operation (Auto-restart)
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BD7679G
( 3 ) DCDC Driver (PWM Comparator, Frequency Hopping, Slope Compensation, OSC, Burst)
BD7672BG uses current mode PWM control. In the internal generator, the average switching frequency is 65 kHz.
Furthermore, switching frequency hopping function is built-in while the switching frequency fluctuation is shown as in
Figure 7. Fluctuation cycle is 125Hz (=8ms).
+4kHz
(+6%)
-4kHz
(-6%)
Figure 7,
Frequency Hopping Function
The max-duty cycle is fix to 75% (Typ) at OUT pin and minimum pulse width is fix at 500ns (Typ). When the duty cycle
exceeds 50% at Current Mode control, the sub-harmonic oscillation occurs. To prevent it, IC is built-in slope
compensation function.
BD7672BG has burst mode function to attain less power consumption when load is light. This function monitors FB pin
voltage and detects light load when FB voltage < VBST (=0.3V Typ).
The secondary output voltage, the FB voltage and the DCDC function are shown in Figure 8.
FB pin is pulled up by RFB (=20kΩ Typ). At light load, when the secondary output voltage rises, the FB pin voltage will
drop and when this goes below VBST (=0.3V Typ) burst function will follow to reduce the power consumption.
Overload
Switching frequency
65kHz
Burst
0.3V
Figure 8,
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FB PIN Voltage
3.6V
Switching Operation Status Changes by FB Pin Voltage
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BD7679G
( 4 ) Over Current Limiter and Leading Edge Blanking Period
BD7679G has over current limiter for each switching cycle.
When the CS pin voltage exceeds the VCS voltage (=0.5V Typ), switching is turned OFF.
In addition, when the driver MOSFET is turned ON, surge current occurs at each capacitor component and drive current.
Therefore, when the CS pin voltage rises temporarily, the detection errors may occur in the over current limiter circuit. To
prevent detection errors, the OUT pin is switched from low to high and the CS signal is blanked for 250nsec by the LEB
(Leading Edge Blanking) function. This blanking function enables a reduction of CS pin noise filtering in response to noise
that occurs when the OUT pin is switched from low to high.
( 5 ) Output Overload Protection Function (FB OLP Comparator )
Overload Protection Function monitors the load status of secondary output through FB pin and stops the switching of OUT
pin during excessive load. In over load condition, there is no current in photo-coupler because output voltage decreases
(drops) while FB pin voltage rises.
When FB pin voltage exceeds VFOLP1A (=3.6V Typ) at TFOLP (=250ms Typ) interval continuously, a load is excessive and
OUT pin is fixed to L. The timer of overload protection is reset when FB pin drops further than VFOLP1B (=3.4V Typ) within
TFOLP (=250ms Typ) after exceeding VFOLP1A (=3.6V Typ). Switching functions within this TFOLP (=250ms Typ).
FB voltage, which is pulled up in resistance to IC internal voltage operates from VFOLP1A (=3.6V Typ) or more at start-up. For
this matter, set the start-up time of the secondary output voltage such that the FB voltage is always VFOLP1B (=3.4V Typ) or
less within TFOLP (=250ms Typ) at start-up.
Figure 9, Overload Protection (Self-restart)
( 6 ) COMP Pin External Stop Function
IC is stopped when the COMP pin voltage rises to VSTOP1 (2.0V Typ). A masking timer for TSTOP (=100us Typ) prepared to
prevent operation errors caused by noise.
Once IC stops by COMP stop function, IC stops until COMP < VSTOP2(=1.8V.Typ).
Overheating Protection by Posistor
When a posistor is attached to the COMP pin shown Figure-10, the switching operation can be stopped when
overheating occurs.
Figure 10 COMP Pin Overheating Protection Application
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Datasheet
BD7679G
●Absolute Maximum Ratings （Ta=25℃）
Symbol
Rating
Unit
Maximum Applied Voltage 1
Parameter
Vmax1
30
V
VCC,
Maximum Applied Voltage 2
Vmax2
6.5
V
CS,
IOUT
±1.0
A
Pd
0.68 (Note1)
OUT pin output Peak Current
Power Dissipation
(Note1)
Operating Temperature Range
Topr
Storage Temperature Range
Tstr
Conditions
W
-40 to +85
o
C
-55 to +150
o
C
OUT
FB,
COMP
When implemented
(Note1) SSOP6: Derate by 5.399 mW/°C when operating above Ta=25°C (when mounted on 70 mm × 70 mm, 1.6 mm thick,
glass epoxy on single-layer substrate).
Caution: Operating the IC over the absolute maximum ratings may damage the IC. The damage can either be a short circuit between pins or an open circuit
between pins and the internal circuitry. Therefore, it is important to consider circuit protection measures, such as adding a fuse, in case the IC is operated over
the absolute maximum ratings.
●Recommended Operating Ratings（Ta=25℃）
Parameter
Symbol
Rating
Unit
VCC
8.5 to 26.0
V
Power Supply Voltage Range
●Electrical Characteristics (Unless otherwise noted, Ta = 25C, VCC=12V)
Specifications
Parameter
Symbol
MIN
TYP
MAX
Conditions
VCC pin voltage
Unit
Conditions
［Circuit Current］
Circuit Current (OFF)
IOFF
-
12
20
μA
VCC = 12V
(UVLO = Detection)
Circuit Current (ON) 1
ION1
-
600
1000
μA
FB = 2.0V COMP: 100kΩ
(during pulse operation)
Circuit Current (ON) 2
ION2
-
400
600
μA
VUVLO1
12.50
13.50
14.50
V
VCC rise
VCC UVLO Voltage 2
VUVLO2
6.50
7.50
8.50
V
VCC drop
VCC UVLO Hysteresis
VUVLO3
-
6.00
-
V
VUVLO3= VUVLO1- VUVLO2
VCC OVP Voltage 1
VOVP1
25.0
27.5
30.0
V
VCC rise
VCC OVP Voltage 2
VOVP2
20.0
22.5
25.0
V
VCC fall
VCC OVP hysteresis
VOVP3
-
5.0
-
V
VOVP3= VOVP1-VOVP2
FB = 0.0V COMP:100kΩ
［VCC Pin Protection Function］
VCC UVLO Voltage 1
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Datasheet
BD7679G
●Electrical Characteristics of control block (Unless otherwise noted, Ta = 25C, VCC=12V)
Specifications
Parameter
Symbol
Unit
MIN
TYP
MAX
Conditions
[PWM Type DCDC Driver Block]
Oscillation Frequency
FSW1
60
65
70
KHz
FB=2.0V
Typ frequency
Frequency Hopping Width 1
FDEL1
-
4.0
-
KHz
FB=2.0V
FCH
93
125
157
Hz
Hopping Fluctuation Frequency
Minimum Pulse Width
Tmin
-
500
-
ns
Soft Start Time 1
TSS1
0.75
1.00
1.25
ms
Soft Start Time 2
TSS2
6.00
8.00
10.00
ms
Maximum Duty 1
Dmax
68.0
75.0
82.0
%
During normal operation
Maximum Duty 2
DSS1
5.0
15.0
25.0
%
During soft start
0[ms] to Tss1[ms]
Maximum Duty 3
DSS2
15.0
25.0
35.0
%
During soft start
TSS1 [ms] to TSS2 [ms]
FB pin Pull-up Resistance
RFB
15
20
25
kΩ
⊿FB / ⊿CS Rain
Gain
-
5
-
V/V
FB Burst Voltage
VBST
0.20
0.30
0.40
V
During FB drop
FB OLP Voltage 1a
VFOLP1A
3.3
3.6
3.9
V
When overload is detected
(FB rise)
FB OLP Voltage 1b
VFOLP1B
-
VFOLP1A-0.
2
-
V
When overload is detected
(FB drop)
TFOLP
187
250
312
ms
Overcurrent Detection Voltage
VCS
0.475
0.500
0.525
V
Leading Edge Blanking Time
TLEB
-
250
-
ns
OUT pin Pch MOS Ron
RPOUT
10
25
39
Ω
OUT pin Nch MOS Ron
RNOUT
3
7
12
Ω
FB OLP Timer
[Overcurrent Detection Block]
[Output Driver Block]
[External stop Comparator Block]
COMP pin stop Detection
Voltage
VSTOP1
1.8
2.0
2.2
V
Rise
COMP pin stop Detection
Voltage
VSTOP2
1.6
1.8
2.0
V
Fall
COMP pin stop Detection
hysteresis
VSTOP3
-
0.2
-
V
VSTOP3 = VSTOP1-VSTOP2
Mask Time for protection
TSTOP
50
100
200
us
VCCOVP, COMP
Mask time
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Datasheet
BD7679G
85.0
83.0
25.0
23.0
68.0
81.0
79.0
77.0
21.0
19.0
17.0
66.0
64.0
62.0
60.0
-40 -25 -10
5
20
35
50
65
MAXDUTY2
(When TYP frequency)[%]
70.0
MAXDUTY1
(When TYP frequency)[%]
TYP FREQ[ｋHz]
●Typical Performance Curves
(This is not a guarantee since this is the reference data. Figure 36 shows the measurement circuit diagram.)
75.0
73.0
71.0
69.0
67.0
65.0
80
-40 -25 -10
Temp[℃ ]
20
35
50
65
80
-40 -25 -10
Figure 12, MAXDUTY1 (With Typ frequency)
20
35
50
65
80
Figure 13, MAXDUTY2 (With Typ frequency）
20
35
50
65
80
10.8
10.3
9.8
9.3
8.8
8.3
7.8
7.3
6.8
6.3
5.8
5.3
4.8
MAXDUTY SS2(VCC=15)[msec]
MAXDUTY SS1(VCC=15）[msec]
5
1.30
1.20
1.10
1.00
0.90
0.80
0.70
0.60
-40 -25 -10
Temp[℃ ]
5
20
35
50
65
80
-40 -25 -10
Temp[℃ ]
Figure 14, MAXDUTY3 (With Typ frequency）
5
20
35
50
65
80
Temp[℃ ]
Figure 15, MAXDUTY SS1 (VCC=15）
Figure 16, MAXDUTY SS2 (VCC=15)
12.0
200.0
11.0
10.0
9.0
8.0
7.0
6.0
5.0
37.0
31.0
28.0
25.0
22.0
19.0
16.0
4.0
13.0
3.0
10.0
-40 -25 -10
5
20
35
50
65
175.0
34.0
TIMER LATCH[us]
PMOS RON(VCC=12)[Ω]
NMOS RON(VCC=12)[Ω]
5
Temp[℃ ]
1.40
35.0
33.0
31.0
29.0
27.0
25.0
23.0
21.0
19.0
17.0
15.0
-40 -25 -10
150.0
125.0
100.0
5
20
35
50
65
80
-40 -25 -10
Temp[℃ ]
10.0
5.0
23.0
21.0
19.0
17.0
15.0
0.0
5
20
35
50
65
80
Temp[℃ ]
Figure 20, ICC (VCC) OFF (VCC=12)
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35
50
65
80
Figure 19, Masking Time
FB OVP 256ms(VCC=12)[ms]
FBRES(VCC=12)[kΩ]
15.0
20
350.0
25.0
20.0
5
Temp[℃ ]
Figure 18, PMOS RON (VCC=12)
Figure 17, NMOS RON (VCC=12)
-40 -25 -10
75.0
50.0
-40 -25 -10
80
Temp[℃ ]
ICC(VCC)OFF(VCC=12)[uA]
9.0
7.0
5.0
Temp[℃ ]
Figure 11, Typ Frequency Fsw1
MAXDUTY3
(When TYP frequency)） [%]
5
15.0
13.0
11.0
-40 -25 -10
5
20
35
50
65
80
Temp[℃ ]
Figure 21, FBRES (VCC=12)
10/17
325.0
300.0
275.0
250.0
225.0
200.0
175.0
150.0
-40 -25 -10
5
20
35
50
65
80
Temp[℃ ]
Figure 22, FBOVP Timer (VCC=12)
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2015.6.24 Rev.002
Datasheet
BD7679G
0.40
0.52
0.51
0.50
0.49
0.48
-40 -25 -10
5
20
35
50
65
80
Temp[℃ ]
70.0
68.0
0.35
TYP FREQ[kHz]
FB Burst Voltage(VCC=12)[V]
CURLIM VOLTAGE(VCC=12)[V]
0.53
0.30
0.25
64.0
62.0
60.0
0.20
-40 -25 -10
5
20
35
50
65
80
Temp[℃ ]
Figure 23, CURLIM Voltage (VCC=12)
66.0
Figure 24, FB Burst Voltage (VCC=12)
8.5
14.0
19.5
25.0
VCC[V]
Figure 25, Frequency Fsw1 (temp=25℃)
CURLIM VOLTAGE(VCC=12)[V]
0.530
0.525
0.520
0.515
0.510
0.505
0.500
0.495
0.490
0.485
0.480
8.5
14.0
19.5
25.0
VCC[V]
Figure 26, CURLIM Voltage (temp=25℃)
BD7679G
Figure 27, Measurement Circuit Diagram
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Datasheet
BD7679G
●Power Dissipation
The thermal design should set the operation for the following conditions.
(Since the temperature shown below is the guaranteed temperature, be sure to take margin into account.)
1. The ambient temperature Ta must be 85℃ or less.
2. The IC’s loss must be within the allowable dissipation Pd.
The thermal reduction characteristics are as follows.
(PCB : 70mm×70mm×1.6mm mounted on glass epoxy substrate)
Figure 28, SSOP6 Thermal Reduction Characteristics
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Datasheet
BD7679G
Operational Notes
1.
Reverse Connection of Power Supply
Connecting the power supply in reverse polarity can damage the IC. Take precautions against reverse polarity when
connecting the power supply, such as mounting an external diode between the power supply and the IC’s power
supply pins.
2.
Power Supply Lines
Design the PCB layout pattern to provide low impedance supply lines. Furthermore, connect a capacitor to ground at
all power supply pins. Consider the effect of temperature and aging on the capacitance value when using electrolytic
capacitors.
3.
Ground Voltage
Ensure that no pins are at a voltage below that of the ground pin at any time, even during transient condition.
4.
Ground Wiring Pattern
When using both small-signal and large-current ground traces, the two ground traces should be routed separately but
connected to a single ground at the reference point of the application board to avoid fluctuations in the small-signal
ground caused by large currents. Also ensure that the ground traces of external components do not cause variations
on the ground voltage. The ground lines must be as short and thick as possible to reduce line impedance.
5.
Thermal Consideration
Should by any chance the power dissipation rating be exceeded the rise in temperature of the chip may result in
deterioration of the properties of the chip. In case of exceeding this absolute maximum rating, increase the board size
and copper area to prevent exceeding the Pd rating.
6.
Recommended Operating Conditions
These conditions represent a range within which the expected characteristics of the IC can be approximately
obtained. The electrical characteristics are guaranteed under the conditions of each parameter.
7.
Inrush Current
When power is first supplied to the IC, it is possible that the internal logic may be unstable and inrush current may
flow instantaneously due to the internal powering sequence and delays, especially if the IC has more than one power
supply. Therefore, give special consideration to power coupling capacitance, power wiring, width of ground wiring,
and routing of connections.
8.
Operation Under Strong Electromagnetic Field
Operating the IC in the presence of a strong electromagnetic field may cause the IC to malfunction.
9.
Testing on Application Boards
When testing the IC on an application board, connecting a capacitor directly to a low-impedance output pin may
subject the IC to stress. Always discharge capacitors completely after each process or step. The IC’s power supply
should always be turned off completely before connecting or removing it from the test setup during the inspection
process. To prevent damage from static discharge, ground the IC during assembly and use similar precautions during
transport and storage.
10. Inter-pin Short and Mounting Errors
Ensure that the direction and position are correct when mounting the IC on the PCB. Incorrect mounting may result in
damaging the IC. Avoid nearby pins being shorted to each other especially to ground, power supply and output pin.
Inter-pin shorts could be due to many reasons such as metal particles, water droplets (in very humid environment)
and unintentional solder bridge deposited in between pins during assembly to name a few.
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Datasheet
BD7679G
Operational Notes – continued
11. Unused Input Pins
Input pins of an IC are often connected to the gate of a MOS transistor. The gate has extremely high impedance and
extremely low capacitance. If left unconnected, the electric field from the outside can easily charge it. The small
charge acquired in this way is enough to produce a significant effect on the conduction through the transistor and
cause unexpected operation of the IC. So unless otherwise specified, unused input pins should be connected to the
power supply or ground line.
12. Regarding the Input Pin of the IC
This monolithic IC contains P+ isolation and P substrate layers between adjacent elements in order to keep them
isolated. P-N junctions are formed at the intersection of the P layers with the N layers of other elements, creating a
parasitic diode or transistor. For example (refer to figure below):
When GND > Pin A and GND > Pin B, the P-N junction operates as a parasitic diode.
When GND > Pin B, the P-N junction operates as a parasitic transistor.
Parasitic diodes inevitably occur in the structure of the IC. The operation of parasitic diodes can result in mutual
interference among circuits, operational faults, or physical damage. Therefore, conditions that cause these diodes to
operate, such as applying a voltage lower than the GND voltage to an input pin (and thus to the P substrate) should
be avoided.
Figure 29. Example of monolithic IC structure
13. Ceramic Capacitor
When using a ceramic capacitor, determine the dielectric constant considering the change of capacitance with
temperature and the decrease in nominal capacitance due to DC bias and others.
14. Area of Safe Operation (ASO)
Operate the IC such that the output voltage, output current, and power dissipation are all within the Area of Safe
Operation (ASO).
15. Thermal Shutdown Circuit(TSD)
This IC has a built-in thermal shutdown circuit that prevents heat damage to the IC. Normal operation should always
be within the IC’s power dissipation rating. If however the rating is exceeded for a continued period, the junction
temperature (Tj) will rise which will activate the TSD circuit that will turn OFF all output pins. When the Tj falls below
the TSD threshold, the circuits are automatically restored to normal operation.
Note that the TSD circuit operates in a situation that exceeds the absolute maximum ratings and therefore, under no
circumstances, should the TSD circuit be used in a set design or for any purpose other than protecting the IC from
heat damage.
16. Over Current Protection Circuit (OCP)
This IC incorporates an integrated overcurrent protection circuit that is activated when the load is shorted. This
protection circuit is effective in preventing damage due to sudden and unexpected incidents. However, the IC should
not be used in applications characterized by continuous operation or transitioning of the protection circuit.
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Datasheet
BD7679G
●Ordering Information
B
D
7
6
7
9
Part Number
G
-
Package
G:SSOP6
G
TR
Packaging and forming specification
TR: Embossed tape and reel
●Physical Dimension Tape and Reel Information
SSOP6
5
0.2Min.
2
Tape
Embossed carrier tape
Quantity
3000pcs
Direction
of feed
TR
The direction is the 1pin of product is at the upper right when you hold
( reel on the left hand and you pull out the tape on the right hand
)
3
1.1±0.05
1
+0.05
0.13 −0.03
1pin
S
+0.05
0.42 −0.04
0.05±0.05
1.25Max.
4
+0.2
1.6 −0.1
2.8±0.2
6
<Tape and Reel information>
+6°
4° −4°
2.9±0.2
0.95
0.1
S
Direction of feed
Reel
(Unit : mm)
∗ Order quantity needs to be multiple of the minimum quantity.
●Marking Diagram
7
9
Part Number Marking
1PIN MARK
LOT Number
SSOP6 (TOP VIEW)
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© 2015 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
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2015.6.24 Rev.002
Datasheet
BD7679G
●Physical Dimension, Tape and Reel Information
Package Name
SSOP6
<Tape and Reel information>
Tape
Embossed carrier tape
Quantity
3000pcs
Direction
of feed
TR
The direction is the 1pin of product is at the upper right when you hold
( reel on the left hand and you pull out the tape on the right hand
)
1pin
Direction of feed
Reel
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© 2015 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
∗ Order quantity needs to be multiple of the minimum quantity.
16/17
TSZ02201-0F2F0A200160-1-2
2015.6.24 Rev.002
Datasheet
BD7679G
●Revision History
Date
Revision
2015.4.17
2015.6.24
001
002
Changes
New preparation
Modify PIN placement in P-11 Figure27
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Datasheet
Notice
Precaution on using ROHM Products
1.
Our Products are designed and manufactured for application in ordinary electronic equipments (such as AV equipment,
OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you
(Note 1)
, transport
intend to use our Products in devices requiring extremely high reliability (such as medical equipment
equipment, traffic equipment, aircraft/spacecraft, nuclear power controllers, fuel controllers, car equipment including car
accessories, safety devices, etc.) and whose malfunction or failure may cause loss of human life, bodily injury or
serious damage to property (“Specific Applications”), please consult with the ROHM sales representative in advance.
Unless otherwise agreed in writing by ROHM in advance, ROHM shall not be in any way responsible or liable for any
damages, expenses or losses incurred by you or third parties arising from the use of any ROHM’s Products for Specific
Applications.
(Note1) Medical Equipment Classification of the Specific Applications
JAPAN
USA
EU
CHINA
CLASSⅢ
CLASSⅡb
CLASSⅢ
CLASSⅢ
CLASSⅣ
CLASSⅢ
2.
ROHM designs and manufactures its Products subject to strict quality control system. However, semiconductor
products can fail or malfunction at a certain rate. Please be sure to implement, at your own responsibilities, adequate
safety measures including but not limited to fail-safe design against the physical injury, damage to any property, which
a failure or malfunction of our Products may cause. The following are examples of safety measures:
[a] Installation of protection circuits or other protective devices to improve system safety
[b] Installation of redundant circuits to reduce the impact of single or multiple circuit failure
3.
Our Products are designed and manufactured for use under standard conditions and not under any special or
extraordinary environments or conditions, as exemplified below. Accordingly, ROHM shall not be in any way
responsible or liable for any damages, expenses or losses arising from the use of any ROHM’s Products under any
special or extraordinary environments or conditions. If you intend to use our Products under any special or
extraordinary environments or conditions (as exemplified below), your independent verification and confirmation of
product performance, reliability, etc, prior to use, must be necessary:
[a] Use of our Products in any types of liquid, including water, oils, chemicals, and organic solvents
[b] Use of our Products outdoors or in places where the Products are exposed to direct sunlight or dust
[c] Use of our Products in places where the Products are exposed to sea wind or corrosive gases, including Cl2,
H2S, NH3, SO2, and NO2
[d] Use of our Products in places where the Products are exposed to static electricity or electromagnetic waves
[e] Use of our Products in proximity to heat-producing components, plastic cords, or other flammable items
[f] Sealing or coating our Products with resin or other coating materials
[g] Use of our Products without cleaning residue of flux (even if you use no-clean type fluxes, cleaning residue of
flux is recommended); or Washing our Products by using water or water-soluble cleaning agents for cleaning
residue after soldering
[h] Use of the Products in places subject to dew condensation
4.
The Products are not subject to radiation-proof design.
5.
Please verify and confirm characteristics of the final or mounted products in using the Products.
6.
In particular, if a transient load (a large amount of load applied in a short period of time, such as pulse. is applied,
confirmation of performance characteristics after on-board mounting is strongly recommended. Avoid applying power
exceeding normal rated power; exceeding the power rating under steady-state loading condition may negatively affect
product performance and reliability.
7.
De-rate Power Dissipation (Pd) depending on Ambient temperature (Ta). When used in sealed area, confirm the actual
ambient temperature.
8.
Confirm that operation temperature is within the specified range described in the product specification.
9.
ROHM shall not be in any way responsible or liable for failure induced under deviant condition from what is defined in
this document.
Precaution for Mounting / Circuit board design
1.
When a highly active halogenous (chlorine, bromine, etc.) flux is used, the residue of flux may negatively affect product
performance and reliability.
2.
In principle, the reflow soldering method must be used on a surface-mount products, the flow soldering method must
be used on a through hole mount products. If the flow soldering method is preferred on a surface-mount products,
please consult with the ROHM representative in advance.
For details, please refer to ROHM Mounting specification
Notice-PGA-E
© 2015 ROHM Co., Ltd. All rights reserved.
Rev.001
Datasheet
Precautions Regarding Application Examples and External Circuits
1.
If change is made to the constant of an external circuit, please allow a sufficient margin considering variations of the
characteristics of the Products and external components, including transient characteristics, as well as static
characteristics.
2.
You agree that application notes, reference designs, and associated data and information contained in this document
are presented only as guidance for Products use. Therefore, in case you use such information, you are solely
responsible for it and you must exercise your own independent verification and judgment in the use of such information
contained in this document. ROHM shall not be in any way responsible or liable for any damages, expenses or losses
incurred by you or third parties arising from the use of such information.
Precaution for Electrostatic
This Product is electrostatic sensitive product, which may be damaged due to electrostatic discharge. Please take proper
caution in your manufacturing process and storage so that voltage exceeding the Products maximum rating will not be
applied to Products. Please take special care under dry condition (e.g. Grounding of human body / equipment / solder iron,
isolation from charged objects, setting of Ionizer, friction prevention and temperature / humidity control).
Precaution for Storage / Transportation
1.
Product performance and soldered connections may deteriorate if the Products are stored in the places where:
[a] the Products are exposed to sea winds or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2
[b] the temperature or humidity exceeds those recommended by ROHM
[c] the Products are exposed to direct sunshine or condensation
[d] the Products are exposed to high Electrostatic
2.
Even under ROHM recommended storage condition, solderability of products out of recommended storage time period
may be degraded. It is strongly recommended to confirm solderability before using Products of which storage time is
exceeding the recommended storage time period.
3.
Store / transport cartons in the correct direction, which is indicated on a carton with a symbol. Otherwise bent leads
may occur due to excessive stress applied when dropping of a carton.
4.
Use Products within the specified time after opening a humidity barrier bag. Baking is required before using Products of
which storage time is exceeding the recommended storage time period.
Precaution for Product Label
QR code printed on ROHM Products label is for ROHM’s internal use only.
Precaution for Disposition
When disposing Products please dispose them properly using an authorized industry waste company.
Precaution for Foreign Exchange and Foreign Trade act
Since concerned goods might be fallen under listed items of export control prescribed by Foreign exchange and Foreign
trade act, please consult with ROHM in case of export.
Precaution Regarding Intellectual Property Rights
1.
All information and data including but not limited to application example contained in this document is for reference
only. ROHM does not warrant that foregoing information or data will not infringe any intellectual property rights or any
other rights of any third party regarding such information or data.
2.
ROHM shall not have any obligations where the claims, actions or demands arising from the combination of the
Products with other articles such as components, circuits, systems or external equipment (including software).
3.
No license, expressly or implied, is granted hereby under any intellectual property rights or other rights of ROHM or any
third parties with respect to the Products or the information contained in this document. Provided, however, that ROHM
will not assert its intellectual property rights or other rights against you or your customers to the extent necessary to
manufacture or sell products containing the Products, subject to the terms and conditions herein.
Other Precaution
1.
This document may not be reprinted or reproduced, in whole or in part, without prior written consent of ROHM.
2.
The Products may not be disassembled, converted, modified, reproduced or otherwise changed without prior written
consent of ROHM.
3.
In no event shall you use in any way whatsoever the Products and the related technical information contained in the
Products or this document for any military purposes, including but not limited to, the development of mass-destruction
weapons.
4.
The proper names of companies or products described in this document are trademarks or registered trademarks of
ROHM, its affiliated companies or third parties.
Notice-PGA-E
© 2015 ROHM Co., Ltd. All rights reserved.
Rev.001
Datasheet
General Precaution
1. Before you use our Pro ducts, you are requested to care fully read this document and fully understand its contents.
ROHM shall n ot be in an y way responsible or liabl e for fa ilure, malfunction or acci dent arising from the use of a ny
ROHM’s Products against warning, caution or note contained in this document.
2. All information contained in this docume nt is current as of the issuing date and subj ect to change without any prior
notice. Before purchasing or using ROHM’s Products, please confirm the la test information with a ROHM sale s
representative.
3.
The information contained in this doc ument is provi ded on an “as is” basis and ROHM does not warrant that all
information contained in this document is accurate an d/or error-free. ROHM shall not be in an y way responsible or
liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccur acy or errors of or
concerning such information.
Notice – WE
© 2015 ROHM Co., Ltd. All rights reserved.
Rev.001