Datasheet L6271, L6270 Datasheet (SGS Thomson Microelectronics)

L6270



90V BCD MIXEDTECHNOLOGY
SO24AND SO20 PLASTICSMDPACKAGE

4.5 TO 13.2V OPERATIVEVOLTAGE
±25 TO ±40V OUTPUT VOLTAGE RANGE

SELECTABLEBY EXTERNALRESISTOR
FULL-WAVE RESONANT DC-DC CON-

VERTER USING SINGLE COIL FOR DUAL
HIGH VOLTAGE GENERATOR WITH OUT­PUT SLEW RATE CONTROL AND SELF
CURRENTLIMITING

LINEARMODE AND BANG-BANGMODE
±40VOR 0/+80VOPERATIVEVOLTAGE
DRIVINGCONFIGURATION MODES:

1.SINGLEENDEDVOLTAGE MODE

2.DIFFERENTIAL VOLTAGE MODE

3.SINGLEENDEDCHARGE MODE

DOUBLEOPERATIONAL AMPLIFIERS WITH
500KHZ GAIN BANDWIDTH PRODUCT AND
LOAD DRIVING CAPABILITY FROM 0.4NF
UP TO24NF

BLOCK DIAGRAM

L6271

MILLI-ACTUATORDRIVER

PRODUCT PREVIEW

SO20 SO24

ORDERING NUMBERS:

L6270 L6271

2.5V VOLTAGEREFERENCE

2.5V ANALOGSHIFTINGCIRCUITRY
POWERSAVING SLEEP MODE

DESCRIPTION

The L6270/1is a piezoelectricactuator driver.

RC

SLEEP

INB-

INB+

COMP

INA-

INA+

HVP

17

-

16

+

HVM

22

HVP

8

-

9

+

HVM

2.5V

50KΩ

7

REFERENCE

SLEEP

ANALOG LEVEL

SHIFTER

VOUT=VIN-2.5

VOUT VIN

V-SHIFTED VIN0-5

CRES

V512-AP COIL HVP

POWER
SUPPLY

1

1

1

1

BAND-GAP

1110

BANG-LIN

K

CONTROLLER

K

K

K

+

-

GND-A VREF

Vfdb

RESONANT

DC-DC

STEP-UP

100µA

+

-

1312

100nF 25KΩ

32120 24

1Ω

INTERNAL
CURRENT

BIAS

14
IREF

COIL

200µA

18
19
23

6
5

20

15
DC2REF
RREFDC

+40V

HBRIDGE1

GND-P2

OUTK-B
OUT1-B

HVM

OUTK-A
OUT1-A

V512A

VSUPPLY

4.5V-13V

100nF

VSUPPLY

D98IN959A

-40V

100nF47nF

February 1999

This is preliminary information on a new product now in development. Details are subjectto change without notice.

1/10

L6270 - L6271

PIN CONNECTION(SO20)

H-BRIDGE

GND-P

COIL

OUT1-A

OUTK-A

SLEEP

INA(inv)

INA(not inv)

GND-A DC2ref

Vref Iref

2
3
4
5
6
7
8
9
10

D98IN968

20
19
18
17
16
15
14
13
12
11

PIN FUNCTIONS(SO20)

N. Name Description

1 H-BRIDGE 40V Half Bridge output for negative charge pump.
2 GND-P Power ground.
3 COIL Coil for positive step up.
4 OUT1-A Output ampl.A.
5 OUTK-A Hi current output ampl.A.
6 SLEEP Sleep mode for stand-by condition(1=SLEEP 0=operative).
7 INA (inv) Inverting input of A-amplifier.
8 INA (not inv) Non Inverting input of A-amplifier.

9 GND-A Analog ground.
10 V
11 I
12 DC2ref Reference voltage for DC-DC converter X20.
13 INB (not inv) Non Invertinginput of B-amplifier.
14 INB (inv) Inverting input of B-amplifier.
15 OUTK-B Hi current output ampl.B.
16 OUT1-B Output ampl.B.
17 V512-AP Analog&Power voltage supply 5 to 12V.
18 RC comp DC-DC converter compensation network.
19 HVM Negative High voltage generated op amp supplier.
20 HVP Positive High voltage generated op amp supplier.

ref

ref

Precise 2.5V reference voltage.
External resistor for precise internal current reference.

HVP1
HVM
RC comp
V512-AP
OUT1-B
OUTK-B
INB(inv)
INB(not inv)

2/10

PIN CONNECTION(SO24)

L6270 - L6271

H-BRIDGE

GND-P

COIL

N.C.

OUT1-A

OUTK-A

SLEEP

INA(inv)
INA(not inv) INB(not inv)
V-SHIFTED DC2ref

2
3
4
5
6
7
8
9
10

24
23
22
21
20
19
18
17
16
15

HVP1
HVM
RC comp
LIN/BANG
V512-AP
OUT1-B
OUTK-B
INB(inv)

Vin 0-5 Iref11 14

1312GND-A Vref

D98IN969

PIN FUNCTIONS(SO24)

N. Name Description

1 H-BRIDGE 40V Half Bridge output for negative charge pump.
2 GND-P Power ground.
3 COIL Coil for positive step up.
4 N.C.
5 OUT1-A Output ampl.A.
6 OUTK-A Hi current output ampl.A.
7 SLEEP Sleep mode for stand-by condition (1=SLEEP 0=operative).
8 INA (inv) Inverting input of A-amplifier.

9 INA (not inv) Non Inverting input of A-amplifier.
10 V-SHIFTED Analog level shifter output Vin-Vref (-2.5 to +2.5 dynamic range)
11 Vin 0-5 Input positive voltage
12 GND-A Analog ground.
13 V
14 I

ref

ref

15 DC2ref Reference voltage for DC-DC converter X20.
16 INB (not inv) Non Inverting input of B-amplifier.
17 INB (inv) Inverting input of B-amplifier.
18 OUTK-B Hi current output ampl.B.
19 OUT1-B Output ampl.B.
20 V512-AP Analog&Power voltage supply 5 to 12V.
21 LIN/BANG Linear or Bang-bang select pin (V512 = BANG 0 = Linear)
22 RC comp DC-DC converter compensation network.
23 HVM Negative High voltage generated op amp supplier.
24 HVP Positive High voltage generated op amp supplier.

Precise 2.5V reference voltage.
External resistor for precise internal current reference.

3/10

L6270 - L6271

ABSOLUTEMAXIMUM RATINGS

Symbol Parameter Value Unit

V512 Supply voltage pin 20 referredto Ground 14 V

HVP Positive high voltage referred to HVM 84 V
HVM Negative high voltage referred to Ground -42 V

IN A&B Amplifier input voltage common mode ±6V

o to 5 Level shifts input voltage -0.5 to +5.5 V

Vi

n

T

amb

T

stg

All the voltagevalue are referred to ground.

Operative Ambient Temperature -20 to +80 °C
Storage Temperature -40to +125 °C

ELECTRICAL CHARACTERISTICS

(All the following parameters are specified @ 27°C and V512 =

12V, unless otherwisespecified.)

Symbol Parameter Test Condition Min. Typ. Max. Unit

V

512

HVP

HVM Output negative voltage -40 -25 V

HVripple HVP,HVM ripple External filter cap. 100nF

DC-DC gain Ratio of HVP and DC-DC ref.

I, hvp Output current (see figure 1a)

I, hvm

T

op

F

switch

R

ds,on

I

boost

CP-slope Charge Pump Slope 150 V/µs

I

sleep

V

ref

I

vref

V

ref, cap

I

ref, res

V

sup

DC gain OpAmp DC gain 130 dB

GBW OpAmp Gain Bandwidth

DCinp OpAmp Input dynamic voltage Double supply -5 5 V

DC-DC

OFF

Main power supply 4.5 13.2 V

(1)

Output positive Voltage Double Supply Voltage 25 40 V

Single Supply Voltage V
Single Supply Voltage V

512
512

≥ 8
≤ 8

30
25

Bang-BangMode

Linear Mode

19 20 21

voltage PIN15

Time to operating condition 5 ms

(2)

Switching Frequency 80 550 kHz
Boost transistor ON resistance 4
Boost transistor current limiting 700 mA

Total current in sleep mode 1 mA
Reference voltage at PIN13 2.4 2.5 2.6 V
Reference voltage output

-1 1 mA

current
Filter capacitor at PIN13 10 100 nF
Resistor at PIN14 for precise

25 k

internal current (100µA)
Minimum OpAmp supply

Voltage (HVP if externally
given)

Double Supply V512

+4

Single Supply V512

+4

product

Cload 0.4nF to 24nF
Double Supply Voltage

500 KHz

Single supply 1.2 10 V

DC-DC Converter switched-off
when DC

2

REF voltage lower

than

80
40

2.5

0.8

0.6 V

V
V

V
V

Ω

Ω

V

V

4/10

L6270 - L6271

ELECTRICALCHARACTERISTICS

(continued)

Symbol Parameter Test Condition Min. Typ. Max. Unit

V

DC, I

out

OpAmp Output dynamic voltage Capacitive load HVM HVP V
OpAmp Bias supply current

bias

7mA

(both)

I

out

PSRR,P OpAmp Positive power supply

OpAmp Dynamic Output current -75 75 mA

@ 50kHz TBD dB

rejection ratio

PSRR,N OpAmp Negative power supply

@ 50kHz TBD dB

rejection ratio

C

load

OpAmp Load capacitance

Voltage mode Gain min 20dB 0.4 24 nF

range

C

int

K OpAmp Current ratio

OpAmp Integration capacitance Charge mode Gain min 20dB 0.4 24 nF

9.8 10 10.2

OUTK/OUT1

(3)

DC

I

err

V

offset

Shift range

OpAmp Ioutk Iout1 = 0 -10 50 µA
OpAmp Input offset voltage
Dynamic Shifter

14V

10 mV

±

Input Range

Note 1: Selectableby externalresistor.
Note 2: Setby external Coil and Capacitor.
Note 3: Itwill be write after silicon characterization, it’s designed for a maximum offset of a few mA.

Incharge mode the Piezo isin openloop, andif Cpiezo= 0.4nF witha maximum Current error of ±5µA the Maximum long time voltage

driftis ±12mV/µs

Figure 1a. HVP load regulation in single supply

mode”.

V

S

(V)

38
36
34
32
30
28
26
24
22

0 0.004 0.008 0.012 0.016 IL(A)

Supply=8V

Supply=5V

D99IN1003

5/10

L6270 - L6271

Figure 1. Charge Mode Configuration (only a suggestion,the applicationis completelyfree

accordingwith ElectricalCharacteristics).

Qpiezo=K*[Cint*(1+Ra/Rb)+C]*Vdac
Qpiezo=Cost*Vdac

HVP

1

Cost=k*[Cint*(1+Ra/Rb)+C]

K

Rb

C

+

-

HVM

Ra

1

Vdac

OPERATIONALAMPLIFIERS DESCRIPTION

Each driver has two output stages scaled in cur­rent by a factorK = 10.
In voltage mode configuration the two outputsare
shorted.
In charge mode configuration OUT1 drives a ca­pacitor Cint and is closed in feedback, while
OUTK drives the piezo, mirroring the current sup­plied to Cint, with a current multiplied by a K fac­tor (see Fig.1).
The supply voltage can be internally generatedby
the DC-DCconverter,or external, maintainingthe
DC-DC converter in sleep mode (PIN15 shorted
to ground), in this case the supply voltage can be
0 to V512+4 minimum value up to 80V in single
supply or V512+4 to 40V symmetricalto ground.

The drivers have 130dB DC gain and the Band­width is 500KHz. Stability is granted with a mini­mum gain of 20dB, for a capacitive load in the
range 0.4nF up to 24nF.

The driverscan be supplied with HVP-HVM (dou­ble supply mode) or with HVP-Ground (single
supply mode). In both cases they can achieve a
rail-to rail output dynamic range with a maximum
load currentof ±75mA.

In double supply mode the input stage has ­5V/+5V dynamic range, while in single supply
modeit has1.2V up to 10V input dynamicrange.

A 2.5V internal reference voltage is available at
one pin (Vref) thatcan be used to close the feed­back if the input signal is symmetrical around

2.5V.
In this case the output dynamic is symmetrical

around 2.5V. It is present a 2.5V down level
shifter that can be connected between the input
signal and the input of the opamp, to work inter-

Cpiezo

K

Cint

D98IN970A

R

P

nally with a signal symmetricalto ground.

DC-DC CONVERTER DESCRIPTION

The DC-DC converterinside the chip can be sup­plied from 5V up to 12V andhas two parts, one to
supplythe positiveand one to supply thenegative
voltage.

The positiveone takes the reference from the pin

2

REF and multiplies it by 20 to have the output

DC
voltage.

2

If DC

REF is lessthan 0.6Vthe whole DC-DC con­verter is shut down and the high voltages have to
be supplied from external. In Sleep Mode (sleep
pin) HVM is shorted to GND. When in singlesup­ply,no loadhas to be connectedto H-bridge output
andHVM mustbe connectedto GND.

The topology is a standard resonant full-wave
boost one: the LC oscillation is kept running all
the time and a set of comparatorsis used to syn­chronize turning on and off of the power MOS in
order to have zero current and zero voltage
switchingand furthermorecontrolledrectification.

The step-up converter is designed to work in
”Bang-Bang” mode and in Linear mode, in this
case an AC compensation network is required
(RC-comp)to guaranteethe stabilityin a wide op­erative range (i.e. changing coil, load, output and
input voltage...).

Bang-Bangmode

In

(Bang/Lin=V512high condi­tion) whenever the output HVP goes down fixed
threshold(Vt

=20⋅DC2REF),the next oscilla-

h,out

tion phase is more powerful and is used to trans­fer energy from the powersupply to the output.

Linear mode

In

, according to the ouput voltage,

the current loaded into the coil is changing like a

6/10

L6270 - L6271

Voltage Loop-Current Controlled system, and in
every pulse there is a regulated power transfer to
the load.

The resonantLC topology has been chosenin or­der to limit the voltage slew-rate across the coil
within reasonable values and so, to minimize irra­diation problems.

The negative converter is a simple charge trans­fer: it is supplied by the positive high voltage and
it capacitively translates this positive voltage

Figure 3. DC-DC converter

HVP

BACK-UP

V512

OSCILL.

+

-

200µA

L

DC-DC
LOGIC

B

:5

L

2.5V

down to a negative one, obviously to limit irradia­tion problems also the chargeoutput has a limited
slew-rate; moreover to reduce intermodulation
phoenomenasthe charge output is synchronized
with the LC oscillationsof the resonant boost.

This negative voltage is (not counting drops on
external rectification diodes) in tracking with the
positive one and so the negativeoutput controller
is notrequired.

V512

V512

+

-

+

-

+

-

R

S

HVP

+40V

HVM

-40V

D98IN971A

7/10

L6270 - L6271

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

A 2.35 2.65 0.093 0.104

A1 0.1 0.3 0.004 0.012

B 0.33 0.51 0.013 0.020

C 0.23 0.32 0.009

D 12.6 13 0.496 0.512

E 7.4 7.6 0.291 0.299

e 1.27 0.050

H 10 10.65 0.394 0.419

h 0.25 0.75 0.010 0.030

L 0.4 1.27 0.016 0.050

K0°(min.)8°(max.)

mm inch

0.013

OUTLINE AND

MECHANICAL DATA

SO20

8/10

B

e

D

1120

110

L

hx45°

A

K

A1

C

H

E

SO20MEC

L6270 - L6271

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

A 2.35 2.65 0.093 0.104

A1 0.10 0.30 0.004 0.012

A2 2.55 0.100

B 0.33 0.51 0.013 0.0200

C 0.23 0.32 0.009

D 15.20 15.60 0.598 0.614

E 7.40 7.60 0.291 0.299

e 1.27 0,050

H 10.0 10.65 0.394 0.419

h 0.25 0.75 0.010 0.030

k0°(min.),8° (max.)

L 0.40 1.27 0.016 0.050

mm inch

0.013

OUTLINE AND

MECHANICAL DATA

SO24

0.10mm
.004

Seating Plane

1

A2

A

Be

A1

K

D

1324

E

12

hx45°

L

A1 C

H

SO24

9/10

L6270 - L6271

Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences
of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is
granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in this publication are
subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products
are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.

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