TEMIC U6229B

U6229B
DC/DC Converter – Power Supply 28 V
Description
converter with external 150 mH inductivity to generate a
7-V auxiliary voltage with a small ripple. By means of
this voltage, two linear regulators with only a small power
dissipation provide a constant 5-V (±3%) supply for
microcontrollers and an even more accurate 5-V (±2%)
supply as a reference for sensors and a/d converters.
The U6229B is a multifunctional power supply IC which
provides four different voltages dedicated to supply
components of complex microcontroller systems.
Supplied by a battery voltage in the wide range from 6 V
to 26 V, the U6229B generates typically 28.4 V with a
step-up converter, PWM, external power MOSFET and
150 mH inductivity. This voltage is fed to a step-down
Features
D Voltage outputs
–
–
–
–
D Analog input VKL15
v
v
28.4-V step-up converter with I 1.2 A
7-V step-down converter with I 400 mA
5-V logic supply with I 14 mA
5-V reference voltage with I 14 mA
v
v
D Logic input ENABLE
– Energy-reserve mode switches off the step-up
converter at VBatt < 5.25 V
– Controls start-up behavior
D Logic output NRES
– N-reset output with over/ under voltage
monitoring of both 5-V supplies
– Enables the step-up converter
Ordering Information
Extended Type Number
U6229B
Package
SO20
Remarks
Block Diagram
28.4 V
Supply
VBatt
VBL
VA1
5V
Logic
supply
7V
Supply
VHL VH
5V
Reference
supply
VCC
VREF
Step-down
converter
GATE
PWM
SOURCE
Step-up
converter
Logic
supply
Reference
voltage
Internal
reference
Over / under
voltage
control
VCC / VREF
SGND
Start-up circuit
and
over voltage
protection
VKL15
GND
ENABLE
Oscillator
OSC
RSET
AGND
NRES
96 12284
Figure 1. Block diagram with external circuit
Rev. A1, 21-Apr-99
1 (8)
Preliminary Information
U6229B
Pin Description
Pin
1
2
3
4
5, 6, 15, 16, 17
7
8
9
10
11
12
13
14
18
19
20
Symbol
OSC
VBL
VA1
SOURCE
SGND
GATE
VHL
VH
VCC
VREF
NRES
ENVA3
VKL15
AGND
RSET1
GND
Input / Output
Analog input
Analog input
Analog output
Analog input
Ground
Analog output
Analog input
Analog output
Analog output
Analog output
Logic output
Logic input
Analog input
Ground
Analog input
Ground
Function
Oscillator
Input set-up converter
Output set-up converter
Source of switching transistor
Ground
Gate of switch transistor
Output of power switch step-down converter
Regulator input step-down converter
5-V supply voltage
5-V reference voltage
Power-on reset
Control step-up converter
Monitoring supply voltage
Reference ground
Connect external resistor to GND – bias of the current sources
Ground
GND
OSC
1
20
VBL
2
19 RSET1
VA1
3
18 AGND
SOURCE
4
17 SGND
SGND
5
16 SGND
SGND
6
15 SGND
GATE
7
14 VKl15
VHL
8
13 ENVA3
VH
9
12 NRES
VCC
10
11 VREF
Functional Description
Oscillator, Pin 1
The switching frequency fosc is defined with (as) a
triangle oscillator and is programmed with the capacitor
COS1.
fosc = Kosc/COS1
Step-up Converter
VBL Pin 2, VA1 Pin 3
The step–up converter uses the battery voltage (6V to
26 V) to produce a constant output voltage (VA1 typ.
28.4 V). An external power MOSFET serves as the
electronic power switch of the step–up converter. When
this switch is activated, the coil current increases up to a
limit determined by the controller. The power MOSFET
is switched off when this limit is reached, and the energy
stored in the coil is discharged into the capacitance CVA1
via the diode and the switches between VBL and VA1. The
maximum possible coil current is limited to typ. 1.2 A by
the circuit.
Figure 2. Pinning U6229B
2 (8)
Rev. A1, 21-Apr-99
Preliminary Information
U6229B
VBatt
VA1
VKL15
VBL
fosc
Load-dump
protection
PWM
VAI
PWM
VH
VHL
GATE
CVA1
SOURCE
CVH
96 12289
96 12288
Figure 3. Basic principle of the step-up converter
SOURCE, Pin 4
A shunt resistor (typ. 180 mW) is connected between the
SOURCE pin and SGND for measurement of the coil current of the step-up converter.
SGND, Pins 5, 6, 15, 16 and 17
SGND is the power ground for the step-up and step-down
converter.
These pins are at the same time metallically connected to
the chip carrier. This results in a very low thermal resistance of the package, which can be significantly
improved by further external measures (large copper
areas or heat sink/metal housing near these pins).
GATE, Pin 7
The push-pull output Pin 7 is designed to trigger a power
MOSFET.In order to protect the external FET, the
maximum output voltage is limited by an integrated
Zener diode.
Step-down Converter
VHL Pin 8, VH Pin 9
Figure 4. Basic principle of the step-down converter
VCC, Pin 10
Output VCC supplies a 5-V voltage suitable for powering
systems with microcontroller. The linear controller
producing this voltage obtains its supply voltage from the
voltage (VH) provided by the step-down converter. VCC
is continuously monitored for any overvoltage or
undervoltage. If such conditions occur, Pin NRES is
switched to ’Low’ for this time. VREF is deactivated
simultaneously.
VREF, Pin 11
Output VREF supplies a precise output voltage of 5V
(+/– 2%) (suitable, for example, as a reference voltage for
an analog-to-digital converter). The linear controller producing this voltage obtains its supply voltage from the
voltage (VH) provided by the step-down converter. VCC
is continuously monitored for any overvoltage or undervoltage. If such conditions occur, Pin NRES is switched
to ’Low’ for this time.
NRES, Pin 12
The step-down converter produces a constant output
voltage (VHtyp. 7 V) from the stepped-up voltage (VA1).
When the integrated electronic power switch of the
step-down converter (Pin VHL) is switched on, the coil
current increases up to a limit determined by the
controller. The switch is switched off when this limit is
reached, and the energy stored in the coil is discharged
into the capacitance CVH via an integrated diode. The
circuit limits the maximum possible coil current to typ.
0.4 A. Pin VH is the controller input of the step-down
converter.
As mentioned, the voltages VCC and VREF are continuously monitored within narrow limits to detect any
overvoltages or undervoltages. A reset signal is issued at
output NRES if overvoltages or undervoltages occur.
NRES = High:
NRES = Low:
Normal operation
Reset state
This function can trigger an error routine or a system reset
in the event of disturbances.Pin NRES is an open collector output, which is protected by a 7-V Zener diode.
Rev. A1, 21-Apr-99
3 (8)
Preliminary Information
U6229B
ENVA3, Pin 13
extended interruptions in the supply voltage. The duration depends on the external load and the size of CVA1.
Pin ENVA3 serves as the control input for the step-up
converter
AGND, Pin 18
ENVA3 = High/ open:
Reference ground for voltages VA1, VH, VCC, VREF and
internal reference
ENVA3 = Low:
Normal operation
Step-up converter switched off
VKl15, Pin 14
VKl15 fulfills several monitoring functions with regard to
the supply voltage.
– Overvoltage detection
The external FET of the step–up converter and the switch
between VA1 and VBL are switched off in the event of
overvoltages of VBatt > 27 V typ. The other parts of the
circuit continue to function and are powered by the
capacitor connected to VA1 during this time. A Zener
diode rated at typ. 23 V is integrated in Pin VKl15 to
protect against overvoltages.
– Energy reserve state
The step-up converter is also switched off at battery voltages of VBatt < 5.25 V. This leads to a reduced current
requirement from VA1. As the step-up converter and the
two linear controllers VCC and VREF are powered by VA1,
the circuit is able to power a system even in the event of
RSET1, Pin 19
Pin 19 is connected to Pin 18 with a resistance of 35.7 kW
(tolerance 1%). In the circuit, this resistance gives rise to
a reference current from which various parameters such
as the oscillator frequency, switch-off thresholds for
step-up/step-down converter, threshold for overvoltage
detection etc. are derived.
GND, Pin 20
Common ground
Starting Behavior
The step-up converter is started only if the following
start-up conditions are fulfilled when it is switched on:
> 5.25 V typ.
VBatt
V3
> 3.4 V typ.
> 3.6 V
VBatt – V3
The step-down converter is activated only if V3 > 7 V typ.
This ensures that the step-down converter begins operation only once the step-up converter has started.
Absolute Maximum Ratings
Parameters
Supply voltage
Ambient temperature range
Junction temperature range
Storage temperature range
Symbol
VBatt
Tamb
Tj
Tstg
Min.
Typ.
–40
–40
–55
Max.
44
95
150
150
Unit
V
°C
°C
°C
Thermal Resistance
Parameters
Junction to case
Junction ambient
Symbol
RthJC
RthJA
Value
30
90
Unit
k/W
k/W
Overvoltage protection according DIN 40839/4 and ISO/TR 7637/1
ESD:
HBM 2 kV: MIL 883D M.3015.7
MM 200 V: ESD S. 5.2 – 1994
4 (8)
Rev. A1, 21-Apr-99
Preliminary Information
U6229B
Electrical Characteristics
VBatt = 6 V to 26 V, Tamb = –40 to 95°C unless otherwise specified. Values measured at application example circuit
figure 5.
Parameters
Oscillator
Frequency constant
Oscillator frequency
Step-up converter
Output voltage
Test Conditions / Pins
COS1 = 1 nF
VCVB = 14 V
Pin 3
I3 = 120 mA
Output voltage
VCVB > 5 V
Pin 3
I3 = 30 mA
Coefficient of efficiency
VCVB = 5 V
V3 = 27.5 V
Coefficient of efficiency
VCVB = 11 V
V3 = 27.5 V
Switch-off current
LVB
Pin 2
Voltage drop
VBL – VA1; I2 = 0.9 I2max
Voltage at pin GATE
Output high
Pin 7
Voltage at pin GATE
Output low
Pin 7
I7 = 100 mA
Voltage at pin GATE
Output low
Pin 7
I7 = 5 mA
Step-up converter – starting behavior
Power-on-reset
VBatt > 6 V
Precharge CVA1
Step-up converter – Enable/Disable
Supply voltage
Threshold voltage
V9 = 7 V
Input voltage
Pin 13 open
Inpu current
V13 = 0 V
Step-down converter
Output voltage
I10 = –20 mA Pin 9
Coefficient of efficiency
Switch-off current
LVH
Pin 8
Voltage drop
VA1 – VHL; I8 = 0.9 I8max
Forward voltage of freeIV8 = 0.9 I8max
wheeling diode
Step-down converter – starting behavior
Switch threshold
VBatt > 6 V
VCC – regulator
Output voltage
IV10 = 0 mA to –90 mA
Switch-off threshold
Undervoltage
Overvoltage
Switch-on threshold
Undervoltage
Overvoltage
Symbol
Min.
Typ.
Max.
Unit
KOSC
fOSC
73
89
HzmF
kHz
VVA1
27.5
28.4
29.3
V
VVA1
27.5
28.4
29.3
V
h
65
%
h
82
%
I2
V2 – V3
V7
V7
1.0
4.5
81
1.2
V7
1.6
3.5
18
1
A
V
V
V
1.6
V
V3
VBatt – V3
2.6
2.1
3.4
4.2
5.5
V
V
VBatt
V13
V13
I13
5.5
0.8
4.4
– 1.9
5.25
5.5
2.0
7.0
– 0.4
V
V
V
V
VH
6.5
70
7.5
V
%
A
V
V
h
I8
V3 – V8
V8
– 0.4
– 0.65
1.3
– 1.2
V3
6.3
7.6
V
V10
dV10off
dV10off
dV10on
dV10on
4.85
5.15
230
230
V
mV
mV
mV
mV
Rev. A1, 21-Apr-99
50
50
5 (8)
Preliminary Information
U6229B
Parameters
VREF – regulator
Output voltage
Switch-off threshold
Test Conditions / Pins
IV11 = –1 mA to –14 mA
Undervoltage
Overvoltage
Undervoltage
Overvoltage
Switch-on threshold
Symbol
Min.
V10
dV11off
dV11off
dV11on
dV11on
4.88
VBatt
26
V14
21
Overvoltage protection
Threshold for overvoltage
detection
Battery monitor
VBatt = 40 V
NRES
Saturation voltage
I12 = 1.6 mA, NRES = low
Reverse current
V12 = 5 V
Typ.
Max.
Unit
5.12
150
150
V
mV
mV
mV
mV
28
V
26
V
0.4
2
V
mA
50
50
V12
Ir12
23
VBatt
RSET
35.7 kW
20
CVREF
2.2 mF
RK15
249 W
19
18
17
16
15
14
13
12
5V
Reference
supply
11
RM
220 W
U6229B
BYG 10
BYG10
1
2
3
4
5
6
7
8
9
LVH
150
mH
COS1
1 nF
SI9955DY
7V
Step-down
converter
28.4 V
Step-up
converter
LVB
150
mH
CVB
100 mF
10
CVA1
1000 mF
CVH
33 mF
CVCC
15 mF
5V
Logic
supply
96 12285
Figure 5. Application example
6 (8)
Rev. A1, 21-Apr-99
Preliminary Information
U6229B
V Batt
Squib
28.4 V
supply
Power
supply
4 Channel squib driver
Sensor
5V
reference
ADC
mC
5V
logic
96 12290
Figure 6. System block diagram
Package Information
9.15
8.65
Package SO20
Dimensions in mm
12.95
12.70
7.5
7.3
2.35
0.25
0.25
0.10
0.4
10.50
10.20
1.27
11.43
20
11
technical drawings
according to DIN
specifications
13038
1
10
Rev. A1, 21-Apr-99
7 (8)
Preliminary Information
U6229B
Ozone Depleting Substances Policy Statement
It is the policy of TEMIC Semiconductor GmbH to
1. Meet all present and future national and international statutory requirements.
2. Regularly and continuously improve the performance of our products, processes, distribution and operating systems
with respect to their impact on the health and safety of our employees and the public, as well as their impact on
the environment.
It is particular concern to control or eliminate releases of those substances into the atmosphere which are known as
ozone depleting substances ( ODSs).
The Montreal Protocol ( 1987) and its London Amendments ( 1990) intend to severely restrict the use of ODSs and
forbid their use within the next ten years. Various national and international initiatives are pressing for an earlier ban
on these substances.
TEMIC Semiconductor GmbH has been able to use its policy of continuous improvements to eliminate the use of
ODSs listed in the following documents.
1. Annex A, B and list of transitional substances of the Montreal Protocol and the London Amendments respectively
2 . Class I and II ozone depleting substances in the Clean Air Act Amendments of 1990 by the Environmental
Protection Agency ( EPA) in the USA
3. Council Decision 88/540/EEC and 91/690/EEC Annex A, B and C ( transitional substances ) respectively.
TEMIC Semiconductor GmbH can certify that our semiconductors are not manufactured with ozone depleting
substances and do not contain such substances.
We reserve the right to make changes to improve technical design and may do so without further notice.
Parameters can vary in different applications. All operating parameters must be validated for each customer
application by the customer. Should the buyer use TEMIC Semiconductors products for any unintended or
unauthorized application, the buyer shall indemnify TEMIC Semiconductors against all claims, costs, damages,
and expenses, arising out of, directly or indirectly, any claim of personal damage, injury or death associated with
such unintended or unauthorized use.
TEMIC Semiconductor GmbH, P.O.B. 3535, D-74025 Heilbronn, Germany
Telephone: 49 ( 0 ) 7131 67 2594, Fax number: 49 ( 0 ) 7131 67 2423
8 (8)
Rev. A1, 21-Apr-99
Preliminary Information