TI TPIC74100QPWPRQ1

TPIC74100-Q1
BUCK/BOOST SWITCH-MODE REGULATOR
www.ti.com
SLIS125 – DECEMBER 2006
•
FEATURES
•
•
•
•
•
Switch-Mode Regulator
– 5 V ±2%, Normal Mode
– 5 V ±3%, Low-Power or Crossover Mode
Switching Frequency, 440 kHz (typical)
Input Operating Range, 1.5 V to 40 V, (Vdriver)
– 1-A Load-Current Capability
– 200-mA Load-Current Capability Down to
2-V Input (Vdriver)
– 120-mA Load-Current Capability Down to
1.5-V Input (Vdriver)
Enable Function
Low-Power Operation Mode
•
•
•
•
Switched 5-V Regulated Output on 5Vg With
Current Limit
Programmable Slew Rate and Frequency
Modulation for EMI Consideration
Reset Function With Deglitch Timer and
Programmable Delay
Alarm Function for Undervoltage Detection
and Indication
Thermally Enhanced Package for Efficient
Heat Management
APPLICATIONS
•
Automotive Electronic Controller Power
Supply
PWP HTSSOP PACKAGE
(TOP VIEW)
1
2
3
4
5
6
7
8
9
10
SCR1
Cboot2
Cboot1
Vdriver
L1
PGND
L2
VOUT
5Vg
AIN
20
19
18
17
16
15
14
13
12
11
SCR0
5Vg_ENABLE
ENABLE
Vlogic
GND
Rmod
REST
AOUT
RESET
CLP
P0021-02
DESCRIPTION
The TPIC74100-Q1 is a switch-mode regulator with integrated switches for voltage-mode control. With the aid of
external components (LC combination), the device regulates the output to 5 V ±3% for a wide input-voltage
range.
The TPIC74100-Q1 offers a reset function to detect and indicate when the 5-V output rail is outside of the
specified tolerance. This reset delay is programmable using an external timing capacitor on the REST terminal.
Additionally, an alarm (AOUT) feature is activated when the input supply rail Vdriver is below a prescaled specified
value (set by the AIN terminal).
The TPIC74100-Q1 has a frequency-modulation scheme to minimize EMI. The clock modulator permits a
modulation of the switching frequency to reduce interference energy in the frequency band.
The 5Vg output is a switched 5-V regulated output with internal current limiting to prevent RESET from being
asserted when powering a capacitive load on the supply line. This function is controlled by the 5Vg_ENABLE
terminal. If there is a short to ground on this output (5Vg output), the output self-protects by operating in a
chopping mode. This does, however, increase the output ripple voltage on VOUT during this fault condition.
Ordering Information
Part Number
TPIC74100QPWPRQ1
Package
R-PDSO-G (PWP, 20-pin)
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PowerPAD is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2006, Texas Instruments Incorporated
TPIC74100-Q1
BUCK/BOOST SWITCH-MODE REGULATOR
www.ti.com
SLIS125 – DECEMBER 2006
Cboot1
Q1
Vdriver
L
Vreg
Vbattery
Charge
Pump
Osc
L1
External Schottky
Diode Required,
Max. 0.4 V
4.7 nF
@1A
@ 125ºC
Q2
22 mH–
100 mH
C
L2
ENABLE
Switch-Mode
Controller With
Dead Time
Vlogic
R2
470 nF
Cboot2
Bandgap
Ref
Q4
AIN
Rmod
R1
4.7 nF
Q3
-
Clock
Modulator
12 kW
+
+
5Vg_ENABLE
VOUT
PGND
Vref
Inrush
Current Limit
5Vg
-
Low-Power Mode
Digital Signal
CLP
Low-Power
Mode
Control
Shutdown
Regulator
Bandgap
Ref
5Vg_Supply
1 µF–100 µF
SCR0
Slew Rate
Control
22 µF–470 µF
Charge
Pump
+
SCR1
5 V Supply
AOUT
Temp
Monitor
POR With
Delay Timer
GND
5 kW
5 kW
RESET
REST
2.2 nF–150 nF
B0130-01
NOTE: All component values are typical.
2
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TPIC74100-Q1
BUCK/BOOST SWITCH-MODE REGULATOR
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SLIS125 – DECEMBER 2006
Table 1. Terminal Functions
TERMINAL
NAME
NO.
I/O
DESCRIPTION
SCR1
1
I
Programmable slew-rate control
Cboot2
2
I
External bootstrap capacitor
Cboot1
3
I
External bootstrap capacitor
Vdriver
4
I
Input voltage source
L1
5
I
Inductor input (an external Schottky diode (1) to GND must be connected to L1)
PGND
6
I
Power ground
L2
7
I
Inductor output
VOUT
8
O
5-V regulated output
5Vg
9
O
Switched 5-V supply
Programmable alarm setting
AIN
10
I
CLP
11
I/O
Low-power operation mode (digital input)
RESET
12
O
Reset function (open drain)
AOUT
13
O
Alarm output (open drain)
REST
14
O
Programmable reset timer delay
Rmod
15
I
Main switching frequency modulation setting to minimize EMI
GND
16
I
Ground
Vlogic
17
O
Supply decoupling output (may be used as a 5-V supply for logic-level inputs)
ENABLE
18
I
Switch-mode regulator enable/disable
5Vg_ENABLE
19
I
Switched 5-V voltage regulator output enable/disable
SCR0
20
I
Programmable slew-rate control
Exposed thermal pad of the package should be connected to GND or left floating.
(1)
Maximum 0.4 V @ 1 A @ 125°C
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TPIC74100-Q1
BUCK/BOOST SWITCH-MODE REGULATOR
www.ti.com
SLIS125 – DECEMBER 2006
ABSOLUTE MAXIMUM RATINGS
over recommended operating free-air temperature range (unless otherwise noted) (1)
Unregulated input voltage, V(driver) (2)
–0.5 V to 40 V
Unregulated inputs, V(AIN), V(ENABLE) (2)
–0.5 V to 40 V
Bootstrap voltages
V(Cboot1)
52 V
V(Cboot2)
Switch mode voltages
14 V
V(L1)
–1 V to 40 V
V(L2)
–1 V to 7 V
Logic input voltages, V(Rmod),V(SCR0),V(SCR1),V(CLP), and V(5Vg_ENABLE)
(2)
–0.5 V to 7 V
Low output voltages, V(RESET),V(AOUT),V(logic), and V(REST) (2)
Electrostatic-discharge
susceptibility
–0.5 V to 7 V
V(HBMESD) (3), pin 7 (L2), pin 8 (VOUT), pin 9 (5Vg)
V(HBMESD)
(3),
800 V
pins 1–6 and 10–20
2 kV
Thermal impedance, junction-to-case, RθJC (4)
Thermal impedance,
junction-to-ambient
2°C/W
RθJA (4)
32°C/W
RθJA (5)
40°C/W
Continuous power dissipation, PD
See Dissipation
Rating Table
Operating virtual junction temperature range, TJ
–40°C to 150°C
Operating ambient temperature range, TA
–40°C to 125°C
Storage temperature range, Tstg
–65°C to 125°C
Lead temperature (soldering, 10 s), T(LEAD)
(1)
(2)
(3)
(4)
(5)
260°C
Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating
conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
All voltage values are with respect to ground.
The human body model is a 100-pF capacitor discharged through a 1.5-kΩ resistor into each terminal.
The thermal data is based on using 2-oz. copper trace with at least four square inches of copper footprint for heat dissipation. The
copper pad is soldered to the thermal land pattern. Correct attachment procedure must be incorporated.
The thermal data is based on using 1-oz. copper trace with at least four square inches of copper footprint for heat dissipation. The
copper pad is soldered to the thermal land pattern. Correct attachment procedure must be incorporated.
DISSIPATION RATING TABLE
RθJA
TA ≤ 25°C Power Rating
Derating Factor Above TA = 25°C
TA = 85°C Power Rating
TA = 125°C Power Rating
32°C/W
3.9 W
31.25 mW/°C
2.03 W
0.781 W
40°C/W
3.125 W
25 mW/°C
1.625 W
0.625 W
RECOMMENDED OPERATING CONDITIONS
Unregulated input voltage, V(driver)
Unregulated input voltages, V(AIN) and V(ENABLE)
Switch-mode terminals
Bootstrap voltages
MAX
6
24
V
V
0
24
V(L1)
–1
17
V(L2)
5
5.5
V(Cboot1)
V(driver) + 10
V(Cboot2)
8
Logic levels (I/O), V(Rmod), V(logic),V(SCR0),V(SCR1),V(5Vg_ENABLE),V(RESET), V(AOUT), V(CLP), and
V(REST)
Operating ambient temperature range, TA
Logic levels (I/O), V(SCR0), V(SCR1), V(CLP) directly connected to V(logic)
4
MIN
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0
UNIT
V
V
5.25
V
–40
125
°C
V(logic)
V(logic)
V
TPIC74100-Q1
BUCK/BOOST SWITCH-MODE REGULATOR
www.ti.com
SLIS125 – DECEMBER 2006
ELECTRICAL CHARACTERISTICS
V(driver) = 6 V to 17 V, TA = -40°C to 125°C, unless otherwise noted
Parameters
TEST CONDITIONS
Min
Typ
1.5
Max
V(driver)
Unregulated input voltage
V(driver)
Start-up condition voltage
CO = 36 µF (min) to 220 µF (max)
4
20
SOM
Soft-start ramp
CO = 220 µF (min) to 470 µF (max), see
Note (1)
2
20
I(standby)
Standby current
ENABLE = low
Iq
Quiescent current
CLP = 0 V, V(driver) = 11 V, IO = 0 mA
VO
Output voltage
DC
IO = 600 mA
V
5
V
10
20
µA
160
µA
V
Normal mode
2%
3%
Output-voltage tolerance
Boost/buck crossover or low-power
mode
IO
Output current
V(driver)≥ 7 V
V(driver) = 2 V, see Note
1
(2)
200
IO(Boost)
Output current, boost mode
IPPn
Internal peak current limit (normal
mode)
(1)
1.75
2.5
IPPl
Internal peak current limit (low-power
mode)
(1)
0.75
1.25
IP
Peak current
V(driver) = 16 V, IO = 1 A, and L = 33 µH
V(driver)
Boost/buck crossover voltage
window
See Note
Tot
Thermal shutdown (4)
V(driver)= 1.5 V, see Note
(2)
(3)
120
1.5
5
160
V/ms
100
5
VO
Unit
40
A
mA
A
A
5.9
V
180
200
°C
135
225
mΩ
400
mA
VO
V
5Vg Output and ENABLE
rDS(on)
On-state resistance
IO
Output current
VI
5Vg_ENABLE input-voltage range
VIH
5Vg_ENABLE threshold high voltage V(5Vg) = 5 V
2.5
3
3.5
V
VIL
5Vg_ENABLE threshold low voltage
1.5
2
2.5
V
V(hys)
Hysteresis voltage
0.5
1
r(pd)
Internal pulldown resistor
300
500
850
kΩ
40
V
–0.5
V(5Vg) = 0 V
V
ENABLE
VI
ENABLE input-voltage range
VIH
ENABLE threshold high voltage
VIL
ENABLE threshold low voltage
V(hys)
(1)
(2)
(3)
(4)
Hysteresis voltage
–0.5
8 V ≤ V(driver) ≤ 17 V
2.5
3
3.5
6 V ≤ V(driver) < 8 V
1.9
3
3.5
VO = 5 V
1.5
2
2.5
8 V ≤ V(driver) ≤ 17 V
0.5
1
6 V ≤ V(driver) < 8 V
0.1
V
V
V
Ensured by characterization.
Tested with inductor having following characteristics: L = 33 µH, Rmax = 0.1 Ω, IR = 1.8 A. Output current must be verified in application
when inductor Rmax (ESR) is increased.
Ensured by characterization. For further details, see the Buck/Boost Transitioning section.
Ensured by characterization; hysteresis 15°C (typical)
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TPIC74100-Q1
BUCK/BOOST SWITCH-MODE REGULATOR
www.ti.com
SLIS125 – DECEMBER 2006
ELECTRICAL CHARACTERISTICS (continued)
V(driver) = 6 V to 17 V, TA = -40°C to 125°C, unless otherwise noted
Parameters
TEST CONDITIONS
Min
Typ
Max
Unit
4.51
4.65
4.79
V
RESET
V(th)
RESET threshold voltage
V(RESET)
RESET tolerance
t(RESET)
RESET time
VOL
RESET output low voltage
t(deglitch)
RESET deglitch time
3%
C(REST) = 10 nF
C(REST)= 100 nF, see Note
(5)
8
10
12
80
100
120
Isink = 5 mA
450
Isink = 1 mA
84
See Note (5)
8
10
ms
mV
12.5
µs
40
V
V
Alarm
VI
Alarm input-voltage range
–0.5
VIL
Alarm threshold low voltage
2.2
2.3
2.35
VIH
Alarm threshold high voltage
2.43
2.5
2.58
V(hys)
Hysteresis voltage
VOL
Alarm output low voltage
200
V
mV
Isink = 5 mA
450
Isink = 1 mA
84
mV
Low-Power Mode (Pulse Mode) PFM
IO(LPM)
Load current in low-power mode
V(driver) < 7 V
II(avg)
Average input current
V(driver) = 11 V, IO = 5 mA, CLP = low
VO
Output-voltage tolerance
VO = 5 V
2.4%
50
mA
3.55
mA
3%
Digital Low-Power Mode (CLP)
VIH
High-level CLP input threshold
voltage
Normal mode
VIL
Low-level CLP input threshold
voltage
Low-power mode
2.6
V
1.15
V
Switching Parameters
f(sw)
V(Rmod) = 0 V, modulator OFF
440
f(sw) = 440 kHz
kHz
18%
f(sw)ac
Operating-frequency accuracy
f(sw)min
Modulation minimum frequency
270
330
445
kHz
f(sw)max
Modulation maximum frequency
450
550
680
kHz
f(mod)span
Modulation span
f(mod)
Modulation frequency
f(mod)ac
Modulation-frequency accuracy
(5)
6
Switching frequency
f(sw) = 440 kHz
20%
220
Rmod = 12 kΩ ±1%
kHz
28
kHz
12%
Ensured by characterization.
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TPIC74100-Q1
BUCK/BOOST SWITCH-MODE REGULATOR
www.ti.com
SLIS125 – DECEMBER 2006
PRINCIPLES OF OPERATION
Functional Principle
The TPIC74100-Q1 is a buck/boost switch-mode regulator that operates in a power-supply concept to ensure a
stable output voltage with input voltage excursions and specified load range.
The device provides an alarm indicator and reset output to interface with systems that require supervisory
function.
The switching regulator offers a clock modulator and a current-mode slew-rate control for the internal switching
transistor (Q1) to minimize EMI.
An internal low-rDS(on) switch has a current-limit feature to prevent inadvertent reset when turning on the 5Vg
output.
Description of the Functional Terminals
Switch-Mode Input/Output Terminals (L1, L2)
The external inductor for the switch-mode regulator is connected between terminals L1 and L2. This inductor is
placed close to the terminals to minimize parasitic effects. For stability, an inductor with 20 µH to 100 µH should
be used.
Supply Terminal (Vdriver)
The input voltage of the device is connected to the Vdriver terminal. This input line requires a filter capacitor to
minimize noise. A low-ESR aluminum or tantalum input capacitor is recommended. The relevant parameters for
the input capacitor are the voltage rating and RMS current rating. The voltage rating should be approximately
1.5 times the maximum applied voltage for an aluminum capacitor and 2 times for a tantalum capacitor. In buck
ǸD * D2
mode, the RMS current is I OUT
, where D is the duty cycle and its maximum RMS current value is
reached when D = 50% with IRMS = IOUT/2. In boost mode, the RMS current is 0.3 × ∆I, where ∆I is the
peak-to-peak ripple current in the inductor. To achieve this, ESR ceramic capacitors are used in parallel with the
aluminum or tantalum capacitors.
Internal Supply Decoupling Terminal (Vlogic)
The Vlogic terminal is used to decouple the internal power-supply noise by use of a 470-nF capacitor. This
terminal can also be used as an output supply for the logic-level inputs for this device (SCR0, SCR1, ENABLE,
CLP, and 5Vg_ENABLE).
Input Voltage Monitoring Terminal (AIN)
The AIN terminal is used to program the threshold voltage for monitoring and detecting undervoltage conditions
on the input supply. A maximum of 40 V may be applied to this terminal and the voltage at this terminal may
exceed the V(driver) input voltage without effecting the device operation. The resistor divider network is
programmed to set the undervoltage detection threshold on this terminal (see the application schematic). The
input has a typical hysteresis of 200 mV with a typical upper limit threshold of 2.5 V and a typical lower limit
threshold of 2.3 V. When V(AIN) falls below 2.3 V, V(AOUT) is asserted low; when V(AIN) exceeds 2.5 V, V(AOUT) is in
the high-impedance state.
The equations to set the upper and lower thresholds of V(AIN) are:
.
Upper:
V(driver) = 2.5 V ×
Lower:
V(driver) = 2.3 V ×
R1 + R2
R1
R1 + R2
R1
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BUCK/BOOST SWITCH-MODE REGULATOR
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SLIS125 – DECEMBER 2006
PRINCIPLES OF OPERATION (continued)
Input Undervoltage Alarm Terminal (AOUT)
The AOUT terminal is an open-drain output that asserts low when the input voltage falls below the set threshold
on the AIN input.
Reset Delay Timer Terminal (REST)
The REST terminal sets the desired delay time to assert the RESET terminal low after the 5-V supply has
exceeded 4.65 V (typical). The delay can be programmed in the range of 2.2 ms to 150 ms using capacitors in
the range of 2.2 nF to 150 nF. The delay time is calculated using the following equation:
RESET delay = C(REST) × 1 ms, where C(REST) has nF units
Reset Terminal (RESET)
The RESET terminal is an open-drain output. The power-on reset output is asserted low until the output voltage
exceeds the 4.65-V threshold and the reset delay timer has expired. Additionally, whenever the ENABLE
terminal is low, RESET is immediately asserted low regardless of the output voltage.
Main Regulator Output Terminal (VOUT)
The VOUT terminal is the output of the switch-mode regulated supply. This terminal requires a filter capacitor with
low-ESR characteristics to minimize output ripple voltage. For stability, a capacitor with 22 µF to 470 µF should
be used. The total capacitance at pin VOUT and pin 5Vg must be less than or equal to 470 µF.
Low-Power-Mode Terminal (CLP)
The CLP terminal controls the low-power mode of the device. An external low digital signal switches the device
to low-power mode or normal mode when the input is high.
Switch-Output Terminal (5Vg)
The 5Vg terminal switches the 5-V regulated output. The output voltage of the regulator can be enabled or
disabled using this low-rDS(on) internal switch. This switch has a current-limiting function to prevent generation of
a reset signal at turnon caused by the capacitive load on the output or overload condition. When the switch is
enabled, the regulated output may deviate and drop momentarily to a tolerance of 7% until the 5Vg capacitor is
fully charged. This deviation depends on the characteristics of the capacitors on VOUT and 5Vg.
5Vg-Enable Terminal (5Vg_ENABLE)
The 5Vg_ENABLE is a logic-level input for enabling the switch output on 5Vg.
For the functional terminal, 5Vg_ENABLE results in the following table:
8
5Vg_ENABLE
Function
0
5Vg is off
Open (internal pulldown = 500 kΩ)
5Vg is off
1
5Vg is on
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BUCK/BOOST SWITCH-MODE REGULATOR
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SLIS125 – DECEMBER 2006
Vdriver
Q1
Peak Current Limit
Switch
Control
Slew Rate Control
L1
Buck/Boost
33 µH
L2
Q4
VOUT
Gate Driver
Q3
47 µF
Q2
Gate
Driver
VOUT
5Vg
5Vg
Charge Pump
typ ~VOUT – 100 mV
100 µF
VOUT
RESET
typ 4.65 V
RESET Deglitch
RESET
5Vg_ENABLE
S0174-01
Figure 1. Current-Limit Switched Output 5Vg
Slew-Rate Control Terminals (SCR0, SCR1)
The slew rate of the switching transistor Q1 is set using the SCR0 and SCR1 terminals.
The following table shows the values of the slew rate (SR):
SCR1
SCR0
0
0
SRQ1
Slow
0
1
Medium-slow
1
0
Medium-fast
1
1
Fast
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BUCK/BOOST SWITCH-MODE REGULATOR
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SLIS125 – DECEMBER 2006
See the converter efficiency plots in the Typical Characteristics section to determine power dissipation.
Modulator Frequency Setting (Terminal Rmod)
The Rmod terminal adjusts the clock modulator frequency. A resistor of Rmod = 12 kΩ generates a modulation
frequency of 28 kHz. The modulator function may be disabled by connecting Rmod to GND and the device
operates with the nominal frequency. The modulator function cannot be activated during IC operation, only at IC
start-up.
Ground Terminal (PGND)
The PGND terminal is the power ground for the device.
Enable Terminal (ENABLE)
The ENABLE terminal allows the enabling and disabling of the switch mode regulator. A maximum of 40 V may
be applied to this terminal to enable the device and increasing it above the V(driver) input voltage does not affect
the device operation.
The functionality of the ENABLE terminal is described in the following table:
ENABLE
Function
0
Vreg is off.
Open
Undefined
1
Vreg is on.
Bootstrap Terminals (Cboot1 and Cboot2)
An external bootstrap capacitor is required for driving the internal high-side MOSFET switch. A 4.7-nF ceramic
capacitor is typically required.
Functional Modes
Clock Modulator
To minimize EMI issues associated with the switch-mode regulator, the device offers an integrated clock
modulator. The function of the clock modulator is to modulate the switching frequency and to distribute the
energy over the wave band.
The average switching frequency is 440 kHz (typical) and varies between 330 kHz and 550 kHz at a rate set by
the Rmod resistor. A typical value of 12 kΩ on the Rmod terminal relates to a 28-kHz modulation frequency. The
clock modulator function can only be activated during IC start-up, not during IC operation.
The equation for the modulation frequency is as follows:
f(mod) (Hz) = (–2.2 × Rmod) + 54.5 kHz, when Rmod = 8 kΩ to 16 kΩ
Buck/Boost Transitioning
The operation mode switches automatically between buck and boost modes depending on the input voltage of
V(driver) and output load conditions. During start up, when V(driver) is less than 5.8 V (typical), the device starts in
boost mode and continues to run in boost mode until V(driver) exceeds 5.8 V; at which time, the device switches
over to buck mode. In buck mode, the device continues to run in buck mode until it is required to switch back to
boost to hold regulation. This crossover window to switch to boost mode is when V(driver) is between 5.8 V and
5 V and depends on the loading conditions. When Vdriver drops below 5.8 V but the device is holding regulation
(~2%), the device remains in buck mode. However, when V(driver) is within the 5.8-V to 5-V window and VOUT
drops to 4.9 V, the device crosses over to boost mode to hold regulation. In boost mode, the device remains in
boost mode until V(driver) exceeds 5.8 V; at which time, the device enters the buck mode. When the device is
10
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BUCK/BOOST SWITCH-MODE REGULATOR
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SLIS125 – DECEMBER 2006
operating in boost mode and V(driver) is in the crossover window of 5.8 V to 5 V, the output regulation may
contain a higher than normal ripple and only maintain a 3% tolerance. This ripple and tolerance depends on the
loading and improves with a higher loading condition. When the device is operated with low-power mode active
(CLP = low) and high output currents (>50 mA), the buck/boost transitioning can cause a reset signal at the
RESET pin.
Buck SMPS
In buck mode, the duty cycle of transistor Q1 sets the voltage VOUT. The duty cycle of transistor Q1 varies 10%
to 99% depending on the input voltage, V(driver). If the peak inductor current (measured by Q1) exceeds 450 mA
(typical), Q2 is turned on for this cycle (synchronized rectification). Otherwise, the current recirculates through
Q2 as a free-wheeling diode. The detection for synchronous or asynchronous mode is done cycle-by-cycle.
To avoid a cross-conduction current between Q1 and Q2, an inherent delay is incorporated when switching Q1
off and Q2 on and vice versa.
In buck mode, transistor Q3 is not required and is switched off. Transistor Q4 is switched on to reduce power
dissipation.
The switch timings for transistors Q3 and Q4 are not considered. In buck mode, the logical control of the
transistors does not change.
Vdriver
Input
Voltage
SMPS
Q1
Current
Control
L1
Q2
33 µH
Switch
Control
L2
Q4
VOUT
Q3
22 µF–470 µF
FB
S0182-01
Figure 2. Buck/Boost Switch Mode Configuration
Boost SMPS
In boost mode, the duty cycle of transistor Q3 controls the output voltage VOUT. The duty cycle is internally
adjusted 5% to 85% depending on the internally sensed voltage of the output. Synchronized rectification occurs
when V(driver) is below 5 V.
To avoid a discharging of the buffer capacitor, a simultaneous switching on of Q3 and Q4 is not allowed. An
inherent delay is incorporated between Q3 switching off and Q4 switching on and vice versa.
In boost mode, transistor Q2 is not required and remains off. Transistor Q1 is switched on for the duration of the
boost-mode operation (serves as a supply line).
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The switch timings of transistors Q1 and Q2 are not considered. In boost mode, the logical control of the
transistors does not change.
Extension of the Input Voltage Range on V(driver)
To ensure a stable 5-V output voltage with the output load in the specified range, the V(driver) supply must be
greater than or equal to 5 V for greater than 1 ms (typical). After a period of 1 ms (typical), the logic may be
supplied by the VOUT regulator and the V(driver) supply may be capable of operating down to 1.5 V.
The switch-mode regulator does not start at V(driver) less than 5 V.
Low-Power Mode
To reduce quiescent current and to provide efficient operation, the regulator enters a pulsed mode.
The device enters this mode by a logic-level low on this terminal.
Automatic low-power mode is not available.The low-power-mode function is not available in boost mode. The
device leaves low-power mode during boost mode regardless of the logic level on the CLP terminal.
Temperature and Short-Circuit Protection
To prevent thermal destruction, the device offers overtemperature protection to disable the IC. Also, short-circuit
protection is included for added protection on VOUT and 5Vg.
Switch Output Terminal (5Vg) Current Limitation
A charge pump drives the internal FET, which switches the primary output voltage VOUT to the 5Vg pin.
Protection is implemented to prevent the output voltage from dropping below its specified value while enabling
the secondary output voltage. An explanation of the block diagram (see Figure 1) is given by the following
example:
• Device is enabled, output voltage VOUT is up and stable.
• 5Vg is enabled (pin 5Vg_ENABLE set to high) with load resistance connected to 5Vg pin.
• If output voltage VOUT drops below typical ( VOUT – 100 mV), the charge pump of the 5Vg FET is switched off
and the FET remains on for a while as the gate voltage drops slowly.
• If VOUT drops below the RESET threshold of 4.65 V (typical), the FET of the secondary output voltage 5Vg is
switched off (gate drawn to ground level).
• A deglitch time ensures that a device reset does not occur if VOUT drops to the reset level during the 5Vg
turnon phase.
• If VOUT rises above typical (VOUT – 100 mV), the charge pump of the 5Vg FET is switched on and drives the
gate of the 5Vg FET on.
Soft Start
On power up, the device offers a soft-start feature which ramps the output of the regulator at a slew of 10 V/ms.
When a reset occurs, the soft start is reenabled. Additionally, if the output capacitor is greater than 220 µF
(typical), the slew rate decreases to a value set by the internal current limit. In boost mode, the soft-start feature
is not active.
12
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BUCK/BOOST SWITCH-MODE REGULATOR
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SLIS125 – DECEMBER 2006
TYPICAL CHARACTERISTICS
6
V(driver) = 11 V
II − Input Current − mA
5
4
Maximum
3
TA = 125°
TA = 25°
2
1
0
0
1
2
3
4
5
6
7
8
9
IO − Output Current − mA
10
G001
NOTE: Maximum characteristic specified by design.
Figure 3. Low-Power Mode Current, IO = 0 mA–10 mA
1.0
V(driver) = 11 V
0.9
II − Input Current − mA
0.8
0.7
0.6
Maximum
0.5
TA = 125°
0.4
TA = 25°
0.3
0.2
0.1
0.0
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
IO − Output Current − mA
0.9
1.0
G002
NOTE: Maximum characteristic specified by design.
Figure 4. Low-Power-Mode Current, IO = 0 mA–1 mA
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SLIS125 – DECEMBER 2006
TYPICAL CHARACTERISTICS (continued)
1100
1000
IO − Output Current − mA
900
TA = 25°
800
700
600
TA = 125°
500
400
300
200
100
0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5 10.0
VI − Input Voltage − V
G003
NOTES:
(1) Typical representation of input voltage vs output load current at TA = 25°C and 125°C, after the correct power-up sequence is
invoked.
(2) The dip in the output current at 5.8 V is caused by the buck/boost transition of the IC.
(3) The output current is clipped to 1 A by the measurement setup.
Figure 5. Typical Input Voltage (V(driver))
vs
Maximum Output Load Current (IO)
85
SCR: 11, V(driver) = 11 V
80
Efficiency − %
75
70
65
SCR: 10, V(driver) = 17 V
SCR: 10, V(driver) = 11 V
60
SCR: 01, V(driver) = 17 V
SCR: 01, V(driver) = 11 V
SCR: 00, V(driver) = 11 V
55
50
100
SCR: 00, V(driver) = 17 V
SCR: 11, V(driver) = 17 V
150
200
250
300
350
400
IO − Output Current − mA
450
500
550
600
G004
NOTE: The average converter efficiency with four different slew rate controls (SCRx) on the Q1 switching FET with input voltage
V(driver) = 11 V and 17 V, TA = 125°C.
Figure 6. Converter Efficiency
14
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SLIS125 – DECEMBER 2006
TYPICAL CHARACTERISTICS (continued)
V(L1)
Input Current
(200 mA/div)
G005
Figure 7. Input Current With Slope Control, SCR0 = 0, SCR1 = 0,
Input-Current Slew Rate = 2.8 A/µs, IL = 500 mA, V(driver) = 15 V
G010
Figure 8. Input Current With Slope Control, SCR1 = 0, SCR0 = 1,
Input-Current Slew Rate = 6.25 A/µs, IL = 500 mA, V(driver) = 15 V
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BUCK/BOOST SWITCH-MODE REGULATOR
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SLIS125 – DECEMBER 2006
TYPICAL CHARACTERISTICS (continued)
G011
Figure 9. Input Current With Slope Control, SCR1 = 1, SCR0 = 0,
Input-Current Slew Rate = 9.4 A/µs, IL = 500 mA, V(driver) = 15 V
G008
Figure 10. Input Current With Slope Control, SCR0 = 1, SCR1 = 1,
Input-Current Slew Rate = 18.8 A/µs, IL = 500 mA, V(driver) = 15 V
16
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TPIC74100-Q1
BUCK/BOOST SWITCH-MODE REGULATOR
SLIS125 – DECEMBER 2006
TYPICAL CHARACTERISTICS (continued)
G009
Figure 11. Low-Power-Mode Operation, IL = 15 mA, CO = 47 µF
G012
Figure 12. Nominal Switching Frequency of Q1 Switch (446 kHz)
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TPIC74100-Q1
BUCK/BOOST SWITCH-MODE REGULATOR
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SLIS125 – DECEMBER 2006
TYPICAL CHARACTERISTICS (continued)
With Modulation Function Disabled, IL = 200 mA
(Reference L1 Terminal, see Figure 13 through Figure 15)
G013
Figure 13. Minimum Switching Frequency (333 kHz)
With Modulation Enabled, Rmod = 12 kΩ, IL = 200 mA
G006
Figure 14. Maximum Switching Frequency (555 kHz)
With Modulation Enabled, Rmod = 12 kΩ, IL = 200 mA
18
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SLIS125 – DECEMBER 2006
TYPICAL CHARACTERISTICS (continued)
(Reference L1 Terminal, see Figure 13 through Figure 15)
G007
Figure 15. Modulation Frequency (Full Span) of 28 kHz
VO
11 V, IL = 700 mA
V(driver)
5V, IL = 700 mA
2V, IL = 225 mA
G014
Figure 16. Input Voltage Excursions (Similar to Low-Crank Conditions)
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TPIC74100-Q1
BUCK/BOOST SWITCH-MODE REGULATOR
www.ti.com
SLIS125 – DECEMBER 2006
TYPICAL CHARACTERISTICS (continued)
(Reference L1 Terminal, see Figure 13 through Figure 15)
G015
Figure 17. Switch-Mode Regulator Transition From Buck Mode to Boost Mode, IL = 400 mA
G016
Figure 18. Switch-Mode Regulator Transition From Boost Mode to Buck Mode, IL = 400 mA
20
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SLIS125 – DECEMBER 2006
TYPICAL CHARACTERISTICS (continued)
(Reference L1 Terminal, see Figure 13 through Figure 15)
Modulation Off
LO G 10 dB /div
Modulation = 28 kHz
G017
LO G 10 dB /div
NOTE: These values represent conducted EMI results of a test board for display purposes only. Actual results may vary greatly
depending on board layout and external components and must be verified in actual application.
Figure 19. Conducted Emissions on Test Board Showing Effects of Switching-Frequency Modulation
Slew Rate = 11
Slew Rate = 00
G018
NOTE: These values represent conducted EMI results of a test board for display purposes only. Actual results may vary greatly
depending on board layout and external components and must be verified in actual application.
Figure 20. Conducted Emissions on Test Board Showing Effects of Minimum and Maximum Slew Rate Settings
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TPIC74100-Q1
BUCK/BOOST SWITCH-MODE REGULATOR
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SLIS125 – DECEMBER 2006
APPLICATION INFORMATION
To maximize the efficiency of this package for application on a single-layer or multilayer PCB, certain guidelines
must be followed when laying out this device on the PCB.
The following information is to be used as a guideline only.
For further information see the PowerPAD Thermally Enhanced Package technical brief (SLMA002).
The following are guidelines for mounting the PowerPAD™ IC on a multilayer PCB with a ground plane.
Solder Pad (Land Pattern)
Package Thermal Pad
Thermal Vias
Package Outline
M0026-01
Figure 21. Package and PCB Land Configuration for a Multilayer PCB
Power Pad
Package Solder Pad
Component Traces
1,5038-mm–1,5748-mm
Component Trace
(2-oz. Cu)
2 Plane
4 Plane
1,5748 mm
Thermal Via
Thermal Isolation
Power Plane Only
1,0142-mm–1,0502-mm
Ground Plane
(1-oz. Cu)
0,5246-mm–0,5606-mm
Power Plane
(1-oz. Cu)
0-mm–0,071-mm Board
Base and Bottom Pad
Package Solder Pad
(Bottom Trace)
M0027-01
Figure 22. Multilayer Board (Side View)
In a multilayer board application, the thermal vias are the primary method of heat transfer from the package
thermal pad to the internal ground plane.
The efficiency of this method depends on several factors (die area, number of thermal vias, thickness of copper,
etc.). See the PowerPAD Thermally Enhanced Package technical brief (SLMA002).
22
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TPIC74100-Q1
BUCK/BOOST SWITCH-MODE REGULATOR
SLIS125 – DECEMBER 2006
APPLICATION INFORMATION (continued)
Use as Much Copper Area
as Possible for Heat Spread
Package Thermal Pad
Package Outline
M0028-01
Figure 23. Land Configuration for Single-Layer PCB
Layout recommendation is to use as much copper area for the power-management section of a single-layer
board as possible. In a single-layer board application, the thermal pad is attached to a heat spreader (copper
areas) by using a low-thermal-impedance attachment method (solder paste or thermal-conductive epoxy). In
both of these cases, it is advisable to use as much copper and as many traces as possible to dissipate the heat.
IMPORTANT
When this attachment method is not implemented correctly, this product may operate inefficiently. Power dissipation capability
may be adversely affected when the device is incorrectly mounted onto the circuit board.
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TPIC74100-Q1
BUCK/BOOST SWITCH-MODE REGULATOR
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SLIS125 – DECEMBER 2006
22 µH–100 µH
4.7 nF
4.7 nF
L1
L2
Cboot1
VOUT
5V
22 µF–470 µF
Cboot2
L
Vbattery
Vdriver
C
5Vg
R2
5V
AIN
1 µF–100 µF
R1
TPIC74100B
5V
ENABLE
5 kW
Vlogic
470 nF
Optional
Connection
RESET
5 kW
5Vg_ENABLE
REST
2.2 nF–150 nF
CLP
AOUT
SCR1
SCR0
Rmod
12 kW
GND
PGND
S0183-01
A.
To minimize voltage ripple on the output due to transients, it is recommended to use a low-ESR capacitor on the
VOUT line.
B.
The L and C component values are system application dependent for EMI consideration.
Figure 24. Application Schematic
Layout Guidelines for Switch-Mode Power Supply
The following guidelines are recommended for PCB layout of the TPIC74100-Q1 device.
Inductor
Use a low-EMI inductor with a ferrite-type closed core. Other types of inductors may be used; however, they
must have low-EMI characteristics and be located away from the low-power traces and components in the
circuit.
Filter Capacitors
Input ceramic filter capacitors should be located in the close proximity of the Vdriver terminal. Surface-mount
capacitors are recommended to minimize lead length and reduce noise coupling.
Traces and Ground Plane
All power (high-current) traces should be thick and as short as possible. The inductor and output capacitors
should be as close to each other as possible. This reduces EMI radiated by the power traces due to high
switching currents.
24
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BUCK/BOOST SWITCH-MODE REGULATOR
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In a two-sided PCB, it is recommended to have ground planes on both sides of the PCB to help reduce noise
and ground-loop errors. The ground connection for the input and output capacitors and IC ground should be
connected to this ground plane.
In a multilayer PCB, the ground plane is used to separate the power plane (where high switching currents and
components are placed) from the signal plane (where the feedback trace and components are) for improved
performance.
Also, arrange the components such that the switching-current loops curl in the same direction. Place the
high-current components such that during conduction, the current path is in the same direction. This prevents
magnetic field reversal caused by the traces between the two half-cycles, helping to reduce radiated EMI.
Buck Mode
• Select inductor ripple current DIL: for example ∆IL = 0.2 × IOUT
• Calculate inductor L:
ǒV IN * V OUTǓ V OUT
L+
f SW DI L V IN
•
•
where fSW is the regulator switching frequency.
Inductor peak current:
DI
I L,max + I OUT ) L
2
Output voltage ripple:
DV OUT + DI L
ǒESR ) 8
Ǔ
1
f SW
COUT
Usually, the first term is dominant.
I pk(t on ) t off)
C OUT +
8 Vripple
•
where fSW is the regulator switching frequency.
Inductor peak current:
DI
I p + I L,max + I IN ) L
2
Output voltage ripple:
I OUT
DV OUT + I p
ESR )
f SW
ǒ1 *
(2)
(3)
(4)
Boost Mode
• Select inductor ripple current ∆IL: for example ∆IL = 0.2 × IIN
• Calculate inductor L:
ǒV OUT * V INǓ V IN
L+
f SW DI L V OUT
•
(1)
V IN
V
(5)
(6)
Ǔ
OUT
COUT
(7)
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25
PACKAGE OPTION ADDENDUM
www.ti.com
6-Mar-2007
PACKAGING INFORMATION
Orderable Device
Status (1)
Package
Type
Package
Drawing
TPIC74100QPWPRQ1
ACTIVE
HTSSOP
PWP
Pins Package Eco Plan (2)
Qty
20
2000 Green (RoHS &
no Sb/Br)
Lead/Ball Finish
CU NIPDAU
MSL Peak Temp (3)
Level-2-260C-1 YEAR
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check
http://www.ti.com/productcontent for the latest availability information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and
package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS
compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder
temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the
accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take
reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on
incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited
information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
to Customer on an annual basis.
Addendum-Page 1
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